.. _devTest_unconvertedExamples:

.. WARNING: DO NOT EDIT THIS FILE:
   AUTOMATICALLY GENERATED.
   PLEASE EDIT THE .py FILE DIRECTLY.

Examples and Demonstrations
===========================

The following examples provide a few samples of some of the
possibilities available when working with music21.

We start loading music21 like this:

    from music21 import *

Searching the Corpus by Locale
------------------------------

This example searches all works in the corpus from two regions in China
for the count and percentage of melodic sevenths. These works come from
the Essen Folksong database, indexed and stored in the ``music21``
corpus.

.. code:: ipython3

    # Get an analysis tool
    diversityTool = analysis.discrete.MelodicIntervalDiversity()
    
    # get a list to store results.
    results = []

.. code:: ipython3

    # Iterate over two regions
    for region in ('shanxi', 'fujian'):
        # Create storage units
        intervalDict = {}
        workCount = 0
        intervalCount = 0
        seventhCount = 0
        
        # Perform a location search on the corpus and iterate over 
        # resulting file name and work number
        for result in corpus.search(region, field='locale'):
            workCount += 1
        
            # Parse the work and create a dictionary of intervals
            s = result.parse()
            intervalDict = diversityTool.countMelodicIntervals(s, found=intervalDict)
        
        # Iterate through all intervals, and count totals and sevenths
        for label in intervalDict.keys():
            intervalCount += intervalDict[label][1] 
            if label in ['m7', 'M7']:
                seventhCount += intervalDict[label][1]
        
        # Calculate a percentage and store results
        pcentSevenths = round((seventhCount / float(intervalCount) * 100), 4)
        results.append((region, pcentSevenths, intervalCount, workCount))

.. code:: ipython3

    # print results
    for region, pcentSevenths, intervalCount, workCount in results: 
        print('locale: {}: found {} percent melodic sevenths, '
              'out of {} intervals in {} works'.format(
                  region, pcentSevenths, intervalCount, workCount))


.. parsed-literal::
   :class: ipython-result

    locale: shanxi: found 3.1994 percent melodic sevenths, out of 4282 intervals in 77 works
    locale: fujian: found 0.7654 percent melodic sevenths, out of 2613 intervals in 53 works


Pitch and Duration Transformations
----------------------------------

This example creates a mensural canon from the Soprano part of a Bach
chorale. The procedure extracts the :class:`~music21.note.Note`
objects from the parsed :class:`~music21.stream.Score` object, using
the :func:`~music21.corpus.parse` function and the
:meth:`~music21.stream.Stream.getElementById` method. Then, a new part
Stream is created by first scaling the timing and duration of events
with the :meth:`~music21.stream.Stream.augmentOrDiminish` method and
then transposing the pitches with the
:meth:`~music21.stream.Stream.transpose` method. The modified Stream
is then inserted into another Stream and displayed with the
:meth:`~music21.base.Music21Object.show` method.

.. code:: ipython3

    src = corpus.parse('bach/bwv323.xml')
    soprano = src.getElementById('Soprano').recurse().notesAndRests.stream()
    soprano.show()



.. image:: devTest_unconvertedExamples_7_0.png
   :width: 708px
   :height: 299px


.. code:: ipython3

    outputScore = stream.Score()
    
    transformations = [(1.0, 'P1'),
                       (2.0, '-P5'),
                       (0.5, '-P11'),
                       (1.5, -24), # 24 semitones down
                      ]
    
    for speed, transposition in transformations:
        part = soprano.augmentOrDiminish(speed)
        part.transpose(transposition, inPlace=True)
        outputScore.insert(0, part)
        
    outputScore.measures(1, 5).show()



.. image:: devTest_unconvertedExamples_8_0.png
   :width: 708px
   :height: 666px