User’s Guide, Chapter 33: Expressions and Ornaments

The previous chapter covered articulations, which music21 defines to mean an expressive mark that applies to a single note, chord, or object. There are two related types of objects which might apply to one or to many notes or other Music21Object instances. These are called in music21, Expressions and their sub-category, Ornaments.

Let’s see what an expression does by playing around with some. We’ll load music21

from music21 import *


To understand how ornaments work, let’s turn to a keyboard piece by C.P.E. Bach and examine the opening two measures:

cpe = corpus.parse('cpebach/h186', forceSource=True)
cpeExcerpt = cpe.measures(1,2)
for n in cpeExcerpt[note.Note]:
    if n.expressions:
        print(n, n.expressions)
 <music21.note.Note C#> [<music21.expressions.Turn>]
 <music21.note.Note B> [<music21.expressions.InvertedMordent>, <music21.expressions.Turn>]
 <music21.note.Note B> [<music21.expressions.Turn>]
cs = cpeExcerpt[note.Note].first()
 <music21.note.Note C#>
 [<music21.note.Note C#>,
  <music21.note.Note D>,
  <music21.note.Note C#>,
  <music21.note.Note B>,
  <music21.note.Note C#>]