music21.mei.base

These are the public interfaces for the MEI module by Christopher Antila

To convert a string with MEI markup into music21 objects, use convertFromString().

In the future, most of the functions in this module should be moved to a separate, import-only module, so that functions for writing music21-to-MEI will fit nicely.

Simple “How-To”

Use MeiToM21Converter to convert a string to a set of music21 objects. In the future, the M21ToMeiConverter class will convert a set of music21 objects into a string with an MEI document.

>>> meiString = """<?xml version="1.0" encoding="UTF-8"?>
... <mei xmlns="http://www.music-encoding.org/ns/mei" meiversion="2013">
...     <music>
...     <score>
...         <scoreDef meter.count="6" meter.unit="8">
...             <staffGrp>
...                 <staffDef n="1" clef.shape="F" clef.line="4"/>
...             </staffGrp>
...         </scoreDef>
...         <section>
...             <scoreDef key.sig="1f" key.mode="major"/>
...             <measure n="1">
...                 <staff n="1">
...                     <layer n="1">
...                         <beam>
...                             <note pname="E" oct="3" dur="8" artic="stacc"/>
...                             <note pname="E" oct="3" dur="8"/>
...                             <note pname="E" oct="3" dur="8"/>
...                         </beam>
...                         <chord dur="4" dots="1">
...                             <note pname="F" oct="2"/>
...                             <note pname="A" oct="2" accid="f"/>
...                         </chord>
...                     </layer>
...                 </staff>
...             </measure>
...         </section>
... </score>
...     </music>
... </mei>
... """
>>> conv = mei.MeiToM21Converter(meiString)
>>> result = conv.run()
>>> result
<music21.stream.Score 0x10ee474f0>

Terminology

This module’s documentation adheres to the following terminology regarding XML documents, using this snippet, <note pname="C"/> as an example:

  • the entire snippet is an element.

  • the word note is the tag.

  • the word pname is an attribute.

  • the letter C is a value.

Because Python also uses “attributes,” an XML attribute is always preceded by an “at sign,” as in @pname, whereas a Python attribute is set as pname.

Ignored Elements

The following elements are not yet imported, though you might expect they would be:

  • <sb>: a system break, since this is not usually semantically significant

  • <lb>: a line break, since this is not usually semantically significant

  • <pb>: a page break, since this is not usually semantically significant

Where Elements Are Processed

Most elements are processed in functions called tagFromElement(), where “tag” is replaced by the element’s tag name (e.g., staffDefFromElement() for <staffDef> elements). These functions convert from a Python xml.etree.ElementTree.Element object to the appropriate music21 object.

However, certain elements are processed primarily in another way, by “private” functions that are not documented in this API. Rather than converting an Element object into a music21 object, these functions modify the MEI document tree by adding instructions for the tagFromElement() functions. The elements processed by private functions include:

  • <slur>

  • <tie>

  • <beamSpan>

  • <tupletSpan>

Whereas you can expect functions like clefFromElement() to convert a <clef> into a Clef with no loss of information. Because we cannot provide a simple one-to-one conversion for slurs, ties, and tuplets, we have kept their conversion functions “private,” to emphasize the fact that you must use the MeiToM21Converter to process them properly.

Guidelines for Encoders

While we aim for the best possible compatibility, the MEI specification is very large. The following guidelines will help you produce a file that this MEI-to-music21 module will import correctly and in the most efficient way. These should not necessarily be considered recommendations when using MEI in any other context.

  • Tuplets indicated only in a @tuplet attribute do not work.

  • For elements that allow @startid, @endid, and @plist attributes, use all three for faster importing.

  • For a <tupletSpan> that does not specify a @plist attribute, a tuplet spanning more than two measures will always and unavoidably be imported incorrectly.

  • For any tuplet, specify at least @num and @numbase. The module refuses to import a tuplet that does not have the @numbase attribute.

  • Retain consistent @n values for the same layer, staff, and instrument throughout the score.

  • Always indicate the duration of <mRest> and <mSpace> elements.

  • Avoid using the <barLine> element if you require well-formatted output from music21, since (as of January 2015) the music21-to-something converters will only output a Barline that is part of a Measure.

List of Supported Elements

Alphabetical list of the elements currently supported by this module:

To know which MEI attributes are known to import correctly, read the documentation for the relevant element. For example, to know whether the @color attribute on a <note> element is supported, read the “Attributes/Elements Implemented” section of the noteFromElement() documentation.

List of Ignored Elements

The following elements are (silently) ignored by the MEI-to-music21 converter because they primarily affect the layout and typesetting of a musical score. We may choose to implement these elements in the future, but they are a lower priority because music21 is not primarily a layout or typesetting tool.

  • <multiRest>: a multi-measure rest (these will be “converted” to single-measure rests)

  • <pb>: a page break

  • <lb>: a line break

  • <sb>: a system break

MeiToM21Converter

class music21.mei.base.MeiToM21Converter(theDocument=None)

A MeiToM21Converter instance manages the conversion of an MEI document into music21 objects.

If theDocument does not have <mei> as the root element, the class raises an MeiElementError. If theDocument is not a valid XML file, the class raises an MeiValidityError.

Parameters:

theDocument (str) – A string containing an MEI document.

Raises:

MeiElementError when the root element is not <mei>

Raises:

MeiValidityError when the MEI file is not valid XML.

MeiToM21Converter methods

MeiToM21Converter.run() → Stream

Run conversion of the internal MEI document to produce a music21 object.

Returns a Stream subclass, depending on the MEI document.

Functions

music21.mei.base.accidFromElement(elem, slurBundle=None)

<accid> Records a temporary alteration to the pitch of a note.

In MEI 2013: pg.248 (262 in PDF) (MEI.shared module)

Returns:

A string indicating the music21 representation of this accidental.

Examples

Unlike most of the ___FromElement() functions, this does not return any music21 object—just a string. Accidentals up to triple-sharp and triple-flat are supported.

>>> from xml.etree import ElementTree as ET
>>> meiSnippet = '<accid accid="s" xmlns="http://www.music-encoding.org/ns/mei"/>'
>>> meiSnippet = ET.fromstring(meiSnippet)
>>> mei.base.accidFromElement(meiSnippet)
'#'
>>> meiSnippet = '<accid accid="tf" xmlns="http://www.music-encoding.org/ns/mei"/>'
>>> meiSnippet = ET.fromstring(meiSnippet)
>>> mei.base.accidFromElement(meiSnippet)
'---'

Attributes/Elements Implemented:

  • @accid (from att.accid.log)

  • @accid.ges (from att.accid.ges)

Note

If set, the @accid.ges attribute is always imported as the music21 Accidental for this note. We assume it corresponds to the accidental implied by a key signature.

Attributes/Elements in Testing: none

Attributes not Implemented:

  • att.common (@label, @n, @xml:base) (att.id (@xml:id))

  • att.facsimile (@facs)

  • att.typography (@fontfam, @fontname, @fontsize, @fontstyle, @fontweight)

  • att.accid.log (@func)

    • (att.controlevent

      • (att.plist (@plist, @evaluate))

      • (att.timestamp.musical (@tstamp))

      • (att.timestamp.performed (@tstamp.ges, @tstamp.real))

      • (att.staffident (@staff)) (att.layerident (@layer)))

  • att.accid.vis (all)

  • att.accid.anl (all)

Contained Elements not Implemented: none

music21.mei.base.articFromElement(elem, slurBundle=None)

<artic> An indication of how to play a note or chord.

In MEI 2013: pg.259 (273 in PDF) (MEI.shared module)

Returns:

A list of Articulation objects.

Examples

This function is normally called by, for example, noteFromElement(), to determine the Articulation objects that will be assigned to the articulations attribute.

>>> from xml.etree import ElementTree as ET
>>> meiSnippet = '<artic artic="acc" xmlns="http://www.music-encoding.org/ns/mei"/>'
>>> meiSnippet = ET.fromstring(meiSnippet)
>>> mei.base.articFromElement(meiSnippet)
[<music21.articulations.Accent>]

A single <artic> element may indicate many Articulation objects.

>>> meiSnippet = '<artic artic="acc ten" xmlns="http://www.music-encoding.org/ns/mei"/>'
>>> meiSnippet = ET.fromstring(meiSnippet)
>>> mei.base.articFromElement(meiSnippet)
[<music21.articulations.Accent>, <music21.articulations.Tenuto>]

Attributes Implemented:

  • @artic

Attributes/Elements in Testing: none

Attributes not Implemented:

  • att.common (@label, @n, @xml:base) (att.id (@xml:id))

  • att.facsimile (@facs)

  • att.typography (@fontfam, @fontname, @fontsize, @fontstyle, @fontweight)

  • att.artic.log

    • (att.controlevent

      • (att.plist (@plist, @evaluate))

      • (att.timestamp.musical (@tstamp))

      • (att.timestamp.performed (@tstamp.ges, @tstamp.real))

      • (att.staffident (@staff))

      • (att.layerident (@layer)))

  • att.artic.vis (all)

  • att.artic.gesatt.artic.anl (all)

Contained Elements not Implemented: none

music21.mei.base.beamFromElement(elem, slurBundle=None)
<beam> A container for a series of explicitly beamed events that begins and ends entirely

within a measure.

In MEI 2013: pg.264 (278 in PDF) (MEI.cmn module)

Parameters:

elem (Element) – The <beam> element to process.

Returns:

An iterable of all the objects contained within the <beam> container.

Return type:

list of Music21Object

Example

Here, three Note objects are beamed together. Take note that the function returns a list of three objects, none of which is a Beam or similar.

>>> from xml.etree import ElementTree as ET
>>> meiSnippet = """<beam xmlns="http://www.music-encoding.org/ns/mei">
...     <note pname='A' oct='7' dur='8'/>
...     <note pname='B' oct='7' dur='8'/>
...     <note pname='C' oct='6' dur='8'/>
... </beam>"""
>>> meiSnippet = ET.fromstring(meiSnippet)
>>> result = mei.base.beamFromElement(meiSnippet)
>>> isinstance(result, list)
True
>>> len(result)
3
>>> result[0].pitch.nameWithOctave
'A7'
>>> result[0].beams
<music21.beam.Beams <music21.beam.Beam 1/start>>
>>> result[1].pitch.nameWithOctave
'B7'
>>> result[1].beams
<music21.beam.Beams <music21.beam.Beam 1/continue>>
>>> result[2].pitch.nameWithOctave
'C6'
>>> result[2].beams
<music21.beam.Beams <music21.beam.Beam 1/stop>>

Attributes/Elements Implemented:

  • <clef>, <chord>, <note>, <rest>, <space>, <tuplet>, <beam>, <barLine>

Attributes/Elements Ignored:

  • @xml:id

Attributes/Elements in Testing: none

Attributes not Implemented:

  • att.common (@label, @n, @xml:base)

  • att.facsimile (@facs)

  • att.beam.log

    • (att.event

      • (att.timestamp.musical (@tstamp))

      • (att.timestamp.performed (@tstamp.ges, @tstamp.real))

      • (att.staffident (@staff))

      • (att.layerident (@layer)))

    • (att.beamedwith (@beam.with))

  • att.beam.vis (all)

  • att.beam.gesatt.beam.anl (all)

Contained Elements not Implemented:

  • MEI.cmn: bTrem beatRpt fTrem halfmRpt meterSig meterSigGrp

  • MEI.critapp: app

  • MEI.edittrans: (all)

  • MEI.mensural: ligature mensur proport

  • MEI.shared: clefGrp custos keySig pad

music21.mei.base.chordFromElement(elem, slurBundle=None)

<chord> is a simultaneous sounding of two or more notes in the same layer with the same duration.

In MEI 2013: pg.280 (294 in PDF) (MEI.shared module)

Attributes/Elements Implemented:

  • @xml:id (or id), an XML id (submitted as the Music21Object “id”)

  • <note> contained within

  • @dur, from att.duration.musical: (via _qlDurationFromAttr())

  • @dots, from att.augmentdots: [0..4]

  • @artic and <artic>

  • @tie, (many of “[i|m|t]”)

  • @slur, (many of “[i|m|t][1-6]”)

  • @grace, from att.note.ges.cmn: partial implementation (notes marked as grace, but the

    duration is 0 because we ignore the question of which neighbouring note to borrow time from)

Attributes/Elements in Testing: none

Attributes not Implemented:

  • att.common (@label, @n, @xml:base)

  • att.facsimile (@facs)

  • att.chord.log

    • (att.event

      • (att.timestamp.musical (@tstamp))

      • (att.timestamp.performed (@tstamp.ges, @tstamp.real))

      • (att.staffident (@staff))

      • (att.layerident (@layer)))

    • (att.fermatapresent (@fermata))

    • (att.syltext (@syl))

    • (att.chord.log.cmn

      • (att.tupletpresent (@tuplet))

      • (att.beamed (@beam))

      • (att.lvpresent (@lv))

      • (att.ornam (@ornam)))

  • att.chord.vis (all)

  • att.chord.ges

    • (att.articulation.performed (@artic.ges))

    • (att.duration.performed (@dur.ges))

    • (att.instrumentident (@instr))

    • (att.chord.ges.cmn (att.graced (@grace, @grace.time))) <– partially implemented

  • att.chord.anl (all)

Contained Elements not Implemented:

  • MEI.edittrans: (all)

music21.mei.base.clefFromElement(elem, slurBundle=None)

<clef> Indication of the exact location of a particular note on the staff and, therefore, the other notes as well.

In MEI 2013: pg.284 (298 in PDF) (MEI.shared module)

Attributes/Elements Implemented:

  • @xml:id (or id), an XML id (submitted as the Music21Object “id”)

  • @shape, from att.clef.gesatt.clef.log

  • @line, from att.clef.gesatt.clef.log

  • @dis, from att.clef.gesatt.clef.log

  • @dis.place, from att.clef.gesatt.clef.log

Attributes/Elements Ignored:

  • @cautionary, since this has no obvious implication for a music21 Clef

  • @octave, since this is likely obscure

Attributes/Elements in Testing: none

Attributes not Implemented:

  • att.common (@label, @n, @xml:base)

  • att.event

    • (att.timestamp.musical (@tstamp))

    • (att.timestamp.performed (@tstamp.ges, @tstamp.real))

    • (att.staffident (@staff))

    • (att.layerident (@layer))

  • att.facsimile (@facs)

  • att.clef.anl (all)

  • att.clef.vis (all)

Contained Elements not Implemented: none

music21.mei.base.dotFromElement(elem, slurBundle=None)

Returns 1 no matter what is passed in.

<dot> Dot of augmentation or division.

In MEI 2013: pg.304 (318 in PDF) (MEI.shared module)

Returns:

1

Return type:

int

Attributes/Elements Implemented: none

Attributes/Elements in Testing: none

Attributes not Implemented:

  • att.common (@label, @n, @xml:base) (att.id (@xml:id))

  • att.facsimile (@facs)

  • att.dot.log (all)

  • att.dot.vis (all)

  • att.dot.gesatt.dot.anl (all)

Elements not Implemented: none

music21.mei.base.instrDefFromElement(elem, slurBundle=None)

<instrDef> (instrument definition)—MIDI instrument declaration.

In MEI 2013: pg.344 (358 in PDF) (MEI.midi module)

Returns:

An Instrument

Attributes/Elements Implemented:

  • @midi.instrname (att.midiinstrument)

  • @midi.instrnum (att.midiinstrument)

Attributes/Elements in Testing: none

Attributes/Elements Ignored:

  • @xml:id

Attributes not Implemented:

  • att.common (@label, @n, @xml:base)

  • att.channelized (@midi.channel, @midi.duty, @midi.port, @midi.track)

  • att.midiinstrument (@midi.pan, @midi.volume)

Contained Elements not Implemented: none

music21.mei.base.layerFromElement(elem, overrideN=None, slurBundle=None)

<layer> An independent stream of events on a staff.

In MEI 2013: pg.353 (367 in PDF) (MEI.shared module)

Note

The Voice object’s id attribute must be set properly in order to ensure continuity of voices between measures. If the elem does not have an @n attribute, you can set one with the overrideN parameter in this function. If you provide a value for overrideN, it will be used instead of the elemn object’s @n attribute.

Because improperly-set id attributes nearly guarantees errors in the imported Score, either overrideN or @n must be specified.

Parameters:

  • elem (Element) – The <layer> element to process.

  • overrideN (str) – The value to be set as the id attribute in the outputted Voice.

Returns:

A Voice with the objects found in the provided Element.

Return type:

music21.stream.Voice

Raises:

MeiAttributeError if neither overrideN nor @n are specified.

Attributes/Elements Implemented:

  • <clef>, <chord>, <note>, <rest>, <mRest>, <beam>, <tuplet>, <space>, <mSpace> , and <barLine> contained within

  • @n, from att.common

Attributes Ignored:

  • @xml:id

Attributes/Elements in Testing: none

Attributes not Implemented:

  • att.common (@label, @xml:base)

  • att.declaring (@decls)

  • att.facsimile (@facs)

  • att.layer.log (@def) and (att.meterconformance (@metcon))

  • att.layer.vis (att.visibility (@visible))

  • att.layer.gesatt.layer.anl (all)

Contained Elements not Implemented:

  • MEI.cmn: arpeg bTrem beamSpan beatRpt bend breath fTrem fermata gliss hairpin halfmRpt

    harpPedal mRpt mRpt2 meterSig meterSigGrp multiRest multiRpt octave pedal reh slur tie tuplet tupletSpan

  • MEI.cmnOrnaments: mordent trill turn

  • MEI.critapp: app

  • MEI.edittrans: (all)

  • MEI.harmony: harm

  • MEI.lyrics: lyrics

  • MEI.mensural: ligature mensur proport

  • MEI.midi: midi

  • MEI.neumes: ineume syllable uneume

  • MEI.shared: accid annot artic barLine clefGrp custos dir dot dynam keySig pad pb phrase sb

    scoreDef staffDef tempo

  • MEI.text: div

  • MEI.usersymbols: anchoredText curve line symbol

music21.mei.base.measureFromElement(elem, backupNum, expectedNs, slurBundle=None, activeMeter=None)

<measure> Unit of musical time consisting of a fixed number of note-values of a given type, as determined by the prevailing meter, and delimited in musical notation by two bar lines.

In MEI 2013: pg.365 (379 in PDF) (MEI.cmn module)

Parameters:

  • elem (Element) – The <measure> element to process.

  • backupNum (int) – A fallback value for the resulting Measure objects’ number attribute.

  • expectedNs (iterable of str) – A list of the expected @n attributes for the <staff> tags in this <measure>. If an expected <staff> isn’t in the <measure>, it will be created with a full-measure rest.

  • activeMeter – The TimeSignature active in this <measure>. This is used to adjust the duration of an <mRest> that was given without a @dur attribute.

Returns:

A dictionary where keys are the @n attributes for <staff> tags found in this <measure>, and values are Measure objects that should be appended to the Part instance with the value’s @n attributes.

Return type:

dict of Measure

Note

When the right barline is set to 'rptboth' in MEI, it requires adjusting the left barline of the following <measure>. If this happens, the Repeat object is assigned to the 'next @left' key in the returned dictionary.

Attributes/Elements Implemented:

  • contained elements: <staff> and <staffDef>

  • @right and @left (att.measure.log)

  • @n (att.common)

Attributes Ignored:

  • @xml:id (att.id)

  • <slur> and <tie> contained within. These spanners will usually be attached to their starting and ending notes with @xml:id attributes, so it’s not necessary to process them when encountered in a <measure>. Furthermore, because the possibility exists for cross-measure slurs and ties, we can’t guarantee we’ll be able to process all spanners until all spanner-attachable objects are processed. So we manage these tags at a higher level.

Attributes/Elements in Testing: none

Attributes not Implemented:

  • att.common (@label, @xml:base)

  • att.declaring (@decls)

  • att.facsimile (@facs)

  • att.typed (@type, @subtype)

  • att.pointing (@xlink:actuate, @xlink:role, @xlink:show, @target, @targettype, @xlink:title)

  • att.measure.log (att.meterconformance.bar (@metcon, @control))

  • att.measure.vis (all)

  • att.measure.ges (att.timestamp.performed (@tstamp.ges, @tstamp.real))

  • att.measure.anl (all)

Contained Elements not Implemented:

  • MEI.cmn: arpeg beamSpan bend breath fermata gliss hairpin harpPedal octave ossia pedal reh

    tupletSpan

  • MEI.cmnOrnaments: mordent trill turn

  • MEI.critapp: app

  • MEI.edittrans: add choice corr damage del gap handShift orig reg restore sic subst supplied

    unclear

  • MEI.harmony: harm

  • MEI.lyrics: lyrics

  • MEI.midi: midi

  • MEI.shared: annot dir dynam pb phrase sb tempo

  • MEI.text: div

  • MEI.usersymbols: anchoredText curve line symbol

music21.mei.base.noteFromElement(elem, slurBundle=None)

<note> is a single pitched event.

In MEI 2013: pg.382 (396 in PDF) (MEI.shared module)

Note

If set, the @accid.ges attribute is always imported as the music21 Accidental for this note. We assume it corresponds to the accidental implied by a key signature.

Note

If elem contains both <syl> and <verse> elements as immediate children, the lyrics indicated with <verse> element(s) will always obliterate those given indicated with <syl> elements.

Attributes/Elements Implemented:

  • @accid and <accid>

  • @accid.ges for key signatures

  • @pname, from att.pitch: [a–g]

  • @oct, from att.octave: [0..9]

  • @dur, from att.duration.musical: (via _qlDurationFromAttr())

  • @dots: [0..4], and <dot> contained within

  • @xml:id (or id), an XML id (submitted as the Music21Object “id”)

  • @artic and <artic>

  • @tie, (many of “[i|m|t]”)

  • @slur, (many of “[i|m|t][1-6]”)

  • @grace, from att.note.ges.cmn: partial implementation (notes marked as grace, but the

    duration is 0 because we ignore the question of which neighbouring note to borrow time from)

  • <syl> and <verse>

Attributes/Elements in Testing: none

Attributes not Implemented:

  • att.common (@label, @n, @xml:base)

  • att.facsimile (@facs)

  • att.note.log

    • (att.event

      • (att.timestamp.musical (@tstamp))

      • (att.timestamp.performed (@tstamp.ges, @tstamp.real))

      • (att.staffident (@staff))

      • (att.layerident (@layer)))

    • (att.fermatapresent (@fermata))

    • (att.syltext (@syl))

    • (att.note.log.cmn

      • (att.tupletpresent (@tuplet))

      • (att.beamed (@beam))

      • (att.lvpresent (@lv))

      • (att.ornam (@ornam)))

    • (att.note.log.mensural (@lig))

  • att.note.vis (all)

  • att.note.ges

    • (@oct.ges, @pname.ges, @pnum)

    • att.articulation.performed (@artic.ges))

    • (att.duration.performed (@dur.ges))

    • (att.instrumentident (@instr))

    • (att.note.ges.cmn (@gliss)

      • (att.graced (@grace, @grace.time))) <– partially implemented

    • (att.note.ges.mensural (att.duration.ratio (@num, @numbase)))

    • (att.note.ges.tablature (@tab.fret, @tab.string))

  • att.note.anl (all)

Contained Elements not Implemented:

  • MEI.critapp: app

  • MEI.edittrans: (all)

music21.mei.base.spaceFromElement(elem, slurBundle=None)

<space> A placeholder used to fill an incomplete measure, layer, etc. most often so that the combined duration of the events equals the number of beats in the measure.

Returns a Rest element with hideObjectOnPrint = True

In MEI 2013: pg.440 (455 in PDF) (MEI.shared module)

music21.mei.base.mSpaceFromElement(elem, slurBundle=None)

<mSpace/> A measure containing only empty space in any meter.

In MEI 2013: pg.377 (391 in PDF) (MEI.cmn module)

This is a function wrapper for spaceFromElement().

Note

If the <mSpace> element does not have a @dur attribute, it will have the default duration of 1.0. This must be fixed later, so the Space object returned from this method is given the m21wasMRest attribute, set to True.

music21.mei.base.restFromElement(elem, slurBundle=None)

<rest/> is a non-sounding event found in the source being transcribed

In MEI 2013: pg.424 (438 in PDF) (MEI.shared module)

Attributes/Elements Implemented:

  • xml:id (or id), an XML id (submitted as the Music21Object “id”)

  • dur, from att.duration.musical: (via _qlDurationFromAttr())

  • dots, from att.augmentdots: [0..4]

Attributes/Elements in Testing: none

Attributes not Implemented:

  • att.common (@label, @n, @xml:base)

  • att.facsimile (@facs)

  • att.rest.log

    • (att.event

      • (att.timestamp.musical (@tstamp))

      • (att.timestamp.performed (@tstamp.ges, @tstamp.real))

      • (att.staffident (@staff))

      • (att.layerident (@layer)))

    • (att.fermatapresent (@fermata))

      • (att.tupletpresent (@tuplet))

      • (att.rest.log.cmn (att.beamed (@beam)))

  • att.rest.vis (all)

  • att.rest.ges (all)

  • att.rest.anl (all)

Contained Elements not Implemented: none

music21.mei.base.mRestFromElement(elem, slurBundle=None)

<mRest/> Complete measure rest in any meter.

In MEI 2013: pg.375 (389 in PDF) (MEI.cmn module)

This is a function wrapper for restFromElement().

Note

If the <mRest> element does not have a @dur attribute, it will have the default duration of 1.0. This must be fixed later, so the Rest object returned from this method is given the m21wasMRest attribute, set to True.

music21.mei.base.scoreFromElement(elem, slurBundle)

<score> Full score view of the musical content.

In MEI 2013: pg.430 (444 in PDF) (MEI.shared module)

Parameters:

  • elem (Element) – The <score> element to process.

  • slurBundle (music21.spanner.SpannerBundle) – This SpannerBundle holds the Slur objects created during pre-processing. The slurs are attached to their respective Note and Chord objects as they are processed.

Returns:

A completed Score object.

Attributes/Elements Implemented:

Attributes Ignored:

Attributes/Elements in Testing:

  • contained <section>, <scoreDef>, and <staffDef>

Attributes not Implemented:

  • att.common (@label, @n, @xml:base) (att.id (@xml:id))

  • att.declaring (@decls)

  • att.typed (@type, @subtype)

  • att.score.anl (att.common.anl (@copyof, @corresp, @next, @prev, @sameas, @synch)

    (att.alignment (@when)))

Contained Elements not Implemented:

  • MEI.critapp: app

  • MEI.edittrans: add choice corr damage del gap handShift orig

    reg restore sic subst supplied unclear

  • MEI.shared: annot ending pb sb

  • MEI.text: div

  • MEI.usersymbols: anchoredText curve line symbol

music21.mei.base.sectionFromElement(elem, allPartNs, activeMeter, nextMeasureLeft, backupMeasureNum, slurBundle)

<section> Segment of music data.

In MEI 2013: pg.432 (446 in PDF) (MEI.shared module)

Note

The parameters and return values are exactly the same for sectionFromElement() and sectionScoreCore(), so refer to the latter function’s documentation for more information.

Attributes/Elements Implemented:

Attributes Ignored:

Attributes/Elements in Testing:

  • @label

  • contained <measure>, <scoreDef>, <staffDef>, <section>

Attributes not Implemented:

  • att.common (@n, @xml:base) (att.id (@xml:id))

  • att.declaring (@decls)

  • att.facsimile (@facs)

  • att.typed (@type, @subtype)

  • att.pointing (@xlink:actuate, @xlink:role, @xlink:show, @target, @targettype, @xlink:title)

  • att.section.vis (@restart)

  • att.section.anl (att.common.anl (@copyof, @corresp, @next, @prev, @sameas, @synch)

    (att.alignment (@when)))

Contained Elements not Implemented:

  • MEI.critapp: app

  • MEI.edittrans: add choice corr damage del gap handShift orig reg

    restore sic subst supplied unclear

  • MEI.shared: annot ending expansion pb sb section staff

  • MEI.text: div

  • MEI.usersymbols: anchoredText curve line symbol

music21.mei.base.scoreDefFromElement(elem, slurBundle=None)

<scoreDef> Container for score meta-information.

In MEI 2013: pg.431 (445 in PDF) (MEI.shared module)

This function returns a dictionary with objects that may relate to the entire score, to all parts at a particular moment, or only to a specific part at a particular moment. The dictionary keys determine the object’s scope. If the key is…

  • 'whole-score objects', it applies to the entire score (e.g., page size);

  • 'all-part objects', it applies to all parts at the moment this <scoreDef> appears;

  • the @n attribute of a part, it applies only to that part at the moment this <scoreDef> appears.

While the multi-part objects will be held in a list, the single-part objects will be in a dict like that returned by staffDefFromElement().

Note that it is the caller’s responsibility to determine the right action if there are conflicting objects in the returned dictionary.

For example:

>>> meiDoc = """<?xml version="1.0" encoding="UTF-8"?>
... <scoreDef meter.count="3" meter.unit="4" xmlns="http://www.music-encoding.org/ns/mei">
...     <staffGrp>
...         <staffDef n="1" label="Clarinet"/>
...         <staffGrp>
...             <staffDef n="2" label="Flute"/>
...             <staffDef n="3" label="Violin"/>
...         </staffGrp>
...     </staffGrp>
... </scoreDef>
... """
>>> from xml.etree import ElementTree as ET
>>> scoreDef = ET.fromstring(meiDoc)
>>> result = mei.base.scoreDefFromElement(scoreDef)
>>> len(result)
5
>>> result['1']
{'instrument': <music21.instrument.Clarinet '1: Clarinet: Clarinet'>}
>>> result['3']
{'instrument': <music21.instrument.Violin '3: Violin: Violin'>}
>>> result['all-part objects']
[<music21.meter.TimeSignature 3/4>]
>>> result['whole-score objects']
[]
Parameters:

elem (Element) – The <scoreDef> element to process.

Returns:

Objects from the <scoreDef>, as described above.

Return type:

dict

Attributes/Elements Implemented:

  • (att.meterSigDefault.log (@meter.count, @meter.unit))

  • (att.keySigDefault.log (@key.accid, @key.mode, @key.pname, @key.sig))

  • contained <staffGrp>

Attributes/Elements in Testing: None

Attributes not Implemented:

  • att.common (@label, @n, @xml:base) (att.id (@xml:id))

  • att.scoreDef.log

    • (att.cleffing.log (@clef.shape, @clef.line, @clef.dis, @clef.dis.place))

    • (att.duration.default (@dur.default, @num.default, @numbase.default))

    • (att.keySigDefault.log (@key.sig.mixed))

    • (att.octavedefault (@octave.default))

    • (att.transposition (@trans.diat, @trans.semi))

    • (att.scoreDef.log.cmn (att.beaming.log (@beam.group, @beam.rests)))

    • (att.scoreDef.log.mensural

      • (att.mensural.log (@mensur.dot, @mensur.sign,

        @mensur.slash, @proport.num, @proport.numbase)

      • (att.mensural.shared (@modusmaior, @modusminor, @prolatio, @tempus))))

  • att.scoreDef.vis (all)

  • att.scoreDef.ges (all)

  • att.scoreDef.anl (none exist)

Contained Elements not Implemented:

  • MEI.cmn: meterSig meterSigGrp

  • MEI.harmony: chordTable

  • MEI.linkalign: timeline

  • MEI.midi: instrGrp

  • MEI.shared: keySig pgFoot pgFoot2 pgHead pgHead2

  • MEI.usersymbols: symbolTable

music21.mei.base.staffFromElement(elem, slurBundle=None)

<staff> A group of equidistant horizontal lines on which notes are placed in order to represent pitch or a grouping element for individual ‘strands’ of notes, rests, etc. that may or may not actually be rendered on staff lines; that is, both diastematic and non-diastematic signs.

In MEI 2013: pg.444 (458 in PDF) (MEI.shared module)

Parameters:

elem (Element) – The <staff> element to process.

Returns:

The Voice classes corresponding to the <layer> tags in elem.

Return type:

list of music21.stream.Voice

Attributes/Elements Implemented:

  • <layer> contained within

Attributes Ignored:

  • @xml:id

Attributes/Elements in Testing: none

Attributes not Implemented:

  • att.common (@label, @n, @xml:base)

  • att.declaring (@decls)

  • att.facsimile (@facs)

  • att.staff.log (@def) (att.meterconformance (@metcon))

  • att.staff.vis (att.visibility (@visible))

  • att.staff.gesatt.staff.anl (all)

Contained Elements not Implemented:

  • MEI.cmn: ossia

  • MEI.critapp: app

  • MEI.edittrans: (all)

  • MEI.shared: annot pb sb scoreDef staffDef

  • MEI.text: div

  • MEI.usersymbols: anchoredText curve line symbol

music21.mei.base.staffDefFromElement(elem, slurBundle=None)

<staffDef> Container for staff meta-information.

In MEI 2013: pg.445 (459 in PDF) (MEI.shared module)

Returns:

A dict with various types of metadata information, depending on what is specified in this <staffDef> element. Read below for more information.

Return type:

dict

Possible Return Values

The contents of the returned dictionary depend on the contents of the <staffDef> element. The dictionary keys correspond to types of information. Possible keys include:

Examples

This <staffDef> only returns a single item.

>>> meiDoc = """<?xml version="1.0" encoding="UTF-8"?>
... <staffDef n="1" label="Clarinet" xmlns="http://www.music-encoding.org/ns/mei"/>
... """
>>> from xml.etree import ElementTree as ET
>>> staffDef = ET.fromstring(meiDoc)
>>> result = mei.base.staffDefFromElement(staffDef)
>>> len(result)
1
>>> result
{'instrument': <music21.instrument.Clarinet '1: Clarinet: Clarinet'>}
>>> result['instrument'].partId
'1'
>>> result['instrument'].partName
'Clarinet'

This <staffDef> returns many objects.

>>> meiDoc = """<?xml version="1.0" encoding="UTF-8"?>
... <staffDef n="2" label="Tuba" key.pname="B" key.accid="f" key.mode="major"
...  xmlns="http://www.music-encoding.org/ns/mei">
...     <clef shape="F" line="4"/>
... </staffDef>
... """
>>> from xml.etree import ElementTree as ET
>>> staffDef = ET.fromstring(meiDoc)
>>> result = mei.base.staffDefFromElement(staffDef)
>>> len(result)
3
>>> result['instrument']
<music21.instrument.Tuba '2: Tuba: Tuba'>
>>> result['clef']
<music21.clef.BassClef>
>>> result['key']
<music21.key.Key of B- major>

Attributes/Elements Implemented:

  • @label (att.common) as Instrument.partName

  • @label.abbr (att.labels.addl) as Instrument.partAbbreviation

  • @n (att.common) as Instrument.partId

  • (att.keySigDefault.log (@key.accid, @key.mode, @key.pname, @key.sig))

  • (att.meterSigDefault.log (@meter.count, @meter.unit))

  • (att.cleffing.log (@clef.shape, @clef.line, @clef.dis, @clef.dis.place)) (via clefFromElement())

  • @trans.diat and @trans.demi (att.transposition)

  • <instrDef> held within

  • <clef> held within

Attributes/Elements Ignored:

  • @key.sig.mixed (from att.keySigDefault.log)

Attributes/Elements in Testing: none

Attributes not Implemented:

  • att.common (@n, @xml:base) (att.id (@xml:id))

  • att.declaring (@decls)

  • att.staffDef.log

    • (att.duration.default (@dur.default, @num.default, @numbase.default))

    • (att.octavedefault (@octave.default))

    • (att.staffDef.log.cmn (att.beaming.log (@beam.group, @beam.rests)))

    • (att.staffDef.log.mensural

      • (att.mensural.log (@mensur.dot, @mensur.sign, @mensur.slash,

        @proport.num, @proport.numbase)

      • (att.mensural.shared (@modusmaior, @modusminor, @prolatio, @tempus))))

  • att.staffDef.vis (all)

  • att.staffDef.ges (all)

  • att.staffDef.anl (none exist)

Contained Elements not Implemented:

  • MEI.cmn: meterSig meterSigGrp

  • MEI.mensural: mensural support

  • MEI.shared: clefGrp keySig label layerDef

music21.mei.base.staffGrpFromElement(elem, slurBundle=None, staffDefDict=None)

<staffGrp> A group of bracketed or braced staves.

In MEI 2013: pg.448 (462 in PDF) (MEI.shared module)

For now, this function is merely a container-processor for <staffDef> elements contained in this <staffGrp> element given as the “elem” argument. That is, the function does not yet create the brackets/braces and labels expected of a staff group. Note however that all <staffDef> elements will be processed, even if they’re contained within several layers of <staffGrp>.

Parameters:

elem (Element) – The <staffGrp> element to process.

Returns:

Dictionary where keys are the @n attribute on a contained <staffDef>, and values are the result of calling staffDefFromElement() with that <staffDef>.

Attributes/Elements Implemented:

  • contained <staffDef>

  • contained <staffGrp>

Attributes/Elements in Testing: none

Attributes not Implemented:

  • att.common (@label, @n, @xml:base) (att.id (@xml:id))

  • att.declaring (@decls)

  • att.facsimile (@facs)

  • att.staffGrp.vis (@barthru)

    • (att.labels.addl (@label.abbr))

    • (att.staffgroupingsym (@symbol))

    • (att.visibility (@visible))

  • att.staffGrp.ges (att.instrumentident (@instr))

Contained Elements not Implemented:

  • MEI.midi: instrDef

  • MEI.shared: grpSym label

music21.mei.base.tupletFromElement(elem, slurBundle=None)

<tuplet> A group of notes with “irregular” (sometimes called “irrational”) rhythmic values, for example, three notes in the time normally occupied by two or nine in the time of five.

In MEI 2013: pg.473 (487 in PDF) (MEI.cmn module)

Parameters:

elem (Element) – The <tuplet> element to process.

Returns:

An iterable of all the objects contained within the <tuplet> container.

Return type:

tuple of Music21Object

Attributes/Elements Implemented:

  • <tuplet>, <beam>, <note>, <rest>, <chord>, <clef>, <space>, <barLine>

  • @num and @numbase

Attributes/Elements in Testing: none

Attributes not Implemented:

  • att.common (@label, @n, @xml:base) (att.id (@xml:id))

  • att.facsimile (@facs)

  • att.tuplet.log

    • (att.event

      • (att.timestamp.musical (@tstamp))

      • (att.timestamp.performed (@tstamp.ges, @tstamp.real))

      • (att.staffident (@staff))

      • (att.layerident (@layer)))

    • (att.beamedwith (@beam.with))

    • (att.augmentdots (@dots))

    • (att.duration.additive (@dur))

    • (att.startendid (@endid) (att.startid (@startid)))

  • att.tuplet.vis (all)

  • att.tuplet.ges (att.duration.performed (@dur.ges))

  • att.tuplet.anl (all)

Contained Elements not Implemented:

  • MEI.cmn: bTrem beatRpt fTrem halfmRpt meterSig meterSigGrp

  • MEI.critapp: app

  • MEI.edittrans: (all)

  • MEI.mensural: ligature mensur proport

  • MEI.shared: clefGrp custos keySig pad

music21.mei.base.addSlurs(elem, obj, slurBundle)

If relevant, add a slur to an obj (object) that was created from an elem (element).

Parameters:

  • elem (xml.etree.ElementTree.Element) – The Element that caused creation of the obj.

  • obj (music21.base.Music21Object) – The musical object (Note, Chord, etc.) created from elem, to which a slur might be attached.

  • slurBundle (music21.spanner.SpannerBundle) – The Slur-holding SpannerBundle associated with the Stream that holds obj.

Returns:

Whether at least one slur was added.

Return type:

bool

A Note about Importing Slurs

Because of how the MEI format specifies slurs, the strategy required for proper import to music21 is not obvious. There are two ways to specify a slur:

  1. With a @slur attribute, in which case addSlurs() reads the attribute and manages creating a Slur object, adding the affected objects to it, and storing the Slur in the slurBundle.

  2. With a <slur> element, which requires pre-processing. In this case, Slur objects must already exist in the slurBundle, and special attributes must be added to the affected elements (@m21SlurStart to the element at the start of the slur and @m21SlurEnd to the element at the end). These attributes hold the id of a Slur in the slurBundle, allowing addSlurs() to find the slur and add obj to it.

Caution

If an elem has an @m21SlurStart or @m21SlurEnd attribute that refer to an object not found in the slurBundle, the slur is silently dropped.

music21.mei.base.allPartsPresent(scoreElem) → tuple[str, ...]

Find the @n values for all <staffDef> elements in a <score> element. This assumes that every MEI <staff> corresponds to a music21 Part.

scoreElem is the <score> Element in which to find the part names. Returns all the unique @n values associated with a part in the <score>.

Example

>>> meiDoc = """<?xml version="1.0" encoding="UTF-8"?>
... <score xmlns="http://www.music-encoding.org/ns/mei">
...     <scoreDef>
...         <staffGrp>
...             <staffDef n="1" clef.shape="G" clef.line="2"/>
...             <staffDef n="2" clef.shape="F" clef.line="4"/>
...         </staffGrp>
...     </scoreDef>
...     <section>
...         <!-- ... some music ... -->
...         <staffDef n="2" clef.shape="C" clef.line="4"/>
...         <!-- ... some music ... -->
...     </section>
... </score>"""
>>> import xml.etree.ElementTree as ETree
>>> meiDoc = ETree.fromstring(meiDoc)
>>> mei.base.allPartsPresent(meiDoc)
('1', '2')

Even though there are three <staffDef> elements in the document, there are only two unique @n attributes. The second appearance of <staffDef> with @n=”2” signals a change of clef on that same staff—not that there is a new staff.

music21.mei.base.barLineFromElement(elem, slurBundle=None)

<barLine> Vertical line drawn through one or more staves that divides musical notation into metrical units.

In MEI 2013: pg.262 (276 in PDF) (MEI.shared module)

Returns:

A music21.bar.Barline or Repeat, depending on the value of @rend. If @rend is 'rptboth', a 2-tuplet of Repeat objects will be returned, represented an “end” and “start” barline, as specified in the music21.bar documentation.

Note

The music21-to-other converters expect that a Barline will be attached to a Measure, which it will not be when imported from MEI as a <barLine> element. However, this function does import correctly to a Barline that you can access from Python in the Stream object as expected.

Attributes/Elements Implemented:

  • @rend from att.barLine.log

Attributes/Elements in Testing: none

Attributes not Implemented:

  • att.common (@label, @n, @xml:base) (att.id (@xml:id))

  • att.facsimile (@facs)

  • att.pointing (@xlink:actuate, @xlink:role, @xlink:show, @target, @targettype, @xlink:title)

  • att.barLine.log

    • (att.meterconformance.bar (@metcon, @control))

  • att.barLine.vis

    • (att.barplacement (@barplace, @taktplace))

    • (att.color (@color))

    • (att.measurement (@unit))

    • (att.width (@width))

  • att.barLine.ges (att.timestamp.musical (@tstamp))

  • att.barLine.anl

    • (att.common.anl

      • (@copyof, @corresp, @next, @prev, @sameas, @synch)

      • (att.alignment (@when)))

Contained Elements not Implemented: none

music21.mei.base.beamTogether(someThings)

Beam some things together. The function beams every object that has a beams attribute, leaving the other objects unmodified.

Parameters:

someThings (iterable of Music21Object) – An iterable of things to beam together.

Returns:

someThings with relevant objects beamed together.

Return type:

same as someThings

music21.mei.base.getVoiceId(fromThese)

From a list of objects with mixed type, find the “id” of the music21.stream.Voice instance.

Parameters:

fromThese (list) – A list of objects of any type, at least one of which must be a Voice instance.

Returns:

The id of the Voice instance.

Raises:

RuntimeError if zero or many Voice objects are found.

music21.mei.base.makeDuration(base: float | int | Fraction = 0.0, dots: int = 0) → duration.Duration

Given a base duration and a number of dots, create a Duration instance with the appropriate quarterLength value.

Returns a Duration corresponding to the fully-augmented value.

Examples

>>> from fractions import Fraction
>>> mei.base.makeDuration(base=2.0, dots=0).quarterLength  # half note, no dots
2.0
>>> mei.base.makeDuration(base=2.0, dots=1).quarterLength  # half note, one dot
3.0
>>> mei.base.makeDuration(base=2, dots=2).quarterLength  # 'base' can be an int or float
3.5
>>> mei.base.makeDuration(2.0, 10).quarterLength  # you want ridiculous dots? Sure...
3.998046875
>>> mei.base.makeDuration(0.33333333333333333333, 0).quarterLength  # works with fractions too
Fraction(1, 3)
>>> mei.base.makeDuration(Fraction(1, 3), 1).quarterLength
0.5
music21.mei.base.makeMetadata(documentRoot)

Produce metadata objects for all the metadata stored in the MEI header.

Parameters:

documentRoot (Element) – The MEI document’s root element.

Returns:

A Metadata object with some of the metadata stored in the MEI document.

Return type:

music21.metadata.Metadata

music21.mei.base.metaSetComposer(work, meta)

From a <work> element, find the composer(s) and store the values in a Metadata object.

Parameters:

  • work – A <work> Element with metadata you want to find.

  • meta – The Metadata object in which to store the metadata.

Returns:

The meta argument, having relevant metadata added.

music21.mei.base.metaSetDate(work, meta)

From a <work> element, find the date (range) of composition and store the values in a Metadata object.

Parameters:

  • work – A <work> Element with metadata you want to find.

  • meta – The Metadata object in which to store the metadata.

Returns:

The meta argument, having relevant metadata added.

music21.mei.base.metaSetTitle(work, meta)

From a <work> element, find the title, subtitle, and movement name (<tempo> element) and store the values in a Metadata object.

Parameters:

  • work – A <work> Element with metadata you want to find.

  • meta – The Metadata object in which to store the metadata.

Returns:

The meta argument, having relevant metadata added.

music21.mei.base.removeOctothorpe(xmlid)

Given a string with an @xml:id to search for, remove a leading octothorpe, if present.

>>> from music21.mei.base import removeOctothorpe
>>> removeOctothorpe('110a923d-a13a-4a2e-b85c-e1d438e4c5d6')
'110a923d-a13a-4a2e-b85c-e1d438e4c5d6'
>>> removeOctothorpe('#e46cbe82-95fc-4522-9f7a-700e41a40c8e')
'e46cbe82-95fc-4522-9f7a-700e41a40c8e'
music21.mei.base.safePitch(name: str, accidental: str | None = None, octave: str | int = '') → Pitch

Safely build a Pitch from a string.

When __init__() is given an empty string, it raises a PitchException. This function instead returns a default Pitch instance.

name: Desired name of the Pitch.

accidental: (Optional) Symbol for the accidental.

octave: (Optional) Octave number.

Returns A Pitch with the appropriate properties.

music21.mei.base.scaleToTuplet(objs, elem)

Scale the duration of some objects by a ratio indicated by a tuplet. The elem must have the @m21TupletNum and @m21TupletNumbase attributes set, and optionally the @m21TupletSearch or @m21TupletType attributes.

The @m21TupletNum and @m21TupletNumbase attributes should be equal to the @num and @numbase values of the <tuplet> or <tupletSpan> that indicates this tuplet.

The @m21TupletSearch attribute, whose value must either be 'start' or 'end', is required when a <tupletSpan> does not include a @plist attribute. It indicates that the importer must “search” for a tuplet near the end of the import process, which involves scaling the durations of all objects discovered between those with the “start” and “end” search values.

The @m21TupletType attribute is set directly as the type attribute of the music21 object’s Tuplet object. If @m21TupletType is not set, the @tuplet attribute will be consulted. Note that this attribute is ignored if the @m21TupletSearch attribute is present, since the type will be set later by the tuplet-finding algorithm.

Note

Objects without a duration attribute will be skipped silently, unless they will be given the @m21TupletSearch attribute.

Parameters:

  • objs ((list of) Music21Object) – The object(s) whose durations will be scaled. You may provide either a single object or an iterable; the return type corresponds to the input type.

  • elem (xml.etree.ElementTree.Element) – An Element with the appropriate attributes (as specified above).

Returns:

objs with scaled durations.

Return type:

(list of) Music21Object

music21.mei.base.sectionScoreCore(elem, allPartNs, slurBundle, *, activeMeter=None, nextMeasureLeft=None, backupMeasureNum=0)

This function is the “core” of both sectionFromElement() and scoreFromElement(), since both elements are treated quite similarly (though not identically). It’s a separate and shared function to reduce code duplication and increase ease of testing. It’s a “public” function to help spread the burden of API documentation complexity: while the parameters and return values are described in this function, the compliance with the MEI Guidelines is described in both sectionFromElement() and scoreFromElement(), as expected.

Required Parameters

Parameters:

  • elem (xml.etree.ElementTree.Element) – The <section> or <score> element to process.

  • allPartNs (iterable of str) – A list or tuple of the expected @n attributes for the <staff> tags in this <section>. This tells the function how many parts there are and what @n values they use.

  • slurBundle (music21.spanner.SpannerBundle) – This SpannerBundle holds the Slur objects created during pre-processing. The slurs are attached to their respective Note and Chord objects as they are processed.

Optional Keyword Parameters

The following parameters are all optional, and must be specified as a keyword argument (i.e., you specify the parameter name before its value).

Parameters:

  • activeMeter (music21.meter.TimeSignature) – The TimeSignature active at the start of this <section> or <score>. This is updated automatically as the music is processed, and the TimeSignature active at the end of the element is returned.

  • nextMeasureLeft (music21.bar.Barline or music21.bar.Repeat) – The @left attribute to use for the next <measure> element encountered. This is used for situations where one <measure> element specified a @right attribute that must be imported by music21 as both the right barline of one measure and the left barline of the following; at the moment this is only @rptboth, which requires a Repeat in both cases.

  • backupMeasureNum (int) – In case a <measure> element is missing its @n attribute, measureFromElement() will use this automatically-incremented number instead. The backupMeasureNum corresponding to the final <measure> in this <score> or <section> is returned from this function.

Returns:

Four-tuple with a dictionary of results, the new value of activeMeter, the new value of nextMeasureLeft, and the new value of backupMeasureNum.

Return type:

(dict, TimeSignature, Barline, int)

Return Value

In short, it’s parsed, activeMeter, nextMeasureLeft, backupMeasureNum.

  • 'parsed' is a dictionary where the keys are the values in allPartNs and the values are

    a list of all the Measure objects in that part, as found in this <section> or <score>.

  • 'activeMeter' is the TimeSignature in effect at the end of this

    <section> or <score>.

  • 'nextMeasureLeft' is the value that should be

    assigned to the leftBarline attribute of the first Measure found in the next <section>. This will almost always be None.

  • 'backupMeasureNum' is equal to the backupMeasureNum argument plus the number of

    <measure> elements found in this <score> or <section>.

music21.mei.base.sylFromElement(elem, slurBundle=None)

<syl> Individual lyric syllable.

In MEI 2013: pg.454 (468 in PDF) (MEI.shared module)

Returns:

An appropriately-configured music21.note.Lyric.

Attributes/Elements Implemented:

  • @con and @wordpos (from att.syl.log)

Attributes/Elements in Testing: none

Attributes not Implemented:

  • att.common (@label, @n, @xml:base) (att.id (@xml:id))

  • att.facsimile (@facs)

  • att.syl.vis (att.typography (@fontfam, @fontname, @fontsize, @fontstyle, @fontweight))

    • (att.visualoffset (att.visualoffset.ho (@ho))

      • (att.visualoffset.to (@to))

      • (att.visualoffset.vo (@vo)))

    • (att.xy (@x, @y))

    • (att.horizontalalign (@halign))

  • att.syl.anl (att.common.anl (@copyof, @corresp, @next, @prev, @sameas, @synch)

    • (att.alignment (@when)))

Contained Elements not Implemented:

  • MEI.edittrans: (all)

  • MEI.figtable: fig

  • MEI.namesdates: corpName geogName periodName persName styleName

  • MEI.ptrref: ptr ref

  • MEI.shared: address bibl date identifier lb name num rend repository stack title

music21.mei.base.verseFromElement(elem, backupN=None, slurBundle=None)

<verse> Lyric verse.

In MEI 2013: pg.480 (494 in PDF) (MEI.lyrics module)

Parameters:

backupN (int) – The backup verse number to use if no @n attribute exists on elem.

Returns:

The appropriately-configured Lyric objects.

Return type:

list of music21.note.Lyric

Attributes/Elements Implemented:

  • @n and <syl>

Attributes/Elements in Testing: none

Attributes not Implemented:

  • att.common (@label, @n, @xml:base) (att.id (@xml:id))

  • att.facsimile (@facs)

  • att.lang (@xml:lang)

  • att.verse.log (@refrain, @rhythm)

  • att.verse.vis (att.typography (@fontfam, @fontname, @fontsize, @fontstyle, @fontweight))

    • (att.visualoffset.to (@to))

    • ((att.visualoffset.vo (@vo))

      • (att.xy (@x, @y))

  • att.verse.anl (att.common.anl (@copyof, @corresp, @next, @prev, @sameas, @synch)

    • (att.alignment (@when)))

Contained Elements not Implemented:

  • MEI.shared: dir dynam lb space tempo