def _getIncipit(self):
'''
Gets the Incipit PolyphonicSnippet of the piece.
The incipit keeps its time signature
in a different location from all the other snippets.
hence, it's a little different
Returns None if the piece or timeSignature is
undefined
>>> bs = alpha.trecento.cadencebook.BallataSheet()
>>> accur = bs.makeWork(2)
>>> accurIncipit = accur.incipit
>>> print(accurIncipit)
<music21.alpha.trecento.polyphonicSnippet.Incipit ...>
'''
rowBlock = self.rowvalues[8:12]
rowBlock.append(self.rowvalues[7])
if (rowBlock[0] == "" or self.timeSigBegin == ""):
return None
else:
blockOut = self.convertBlockToStreams(rowBlock)
return polyphonicSnippet.Incipit(blockOut, self)
def getSnippetAtPosition(self, snippetPosition, snippetType="end"):
'''
gets a "snippet" which is a collection of up to 3 lines of music, a timeSignature
and a description of the cadence.
>>> bs = alpha.trecento.cadencebook.BallataSheet()
>>> accur = bs.makeWork(2)
>>> print(accur.getSnippetAtPosition(12))
<music21.alpha.trecento.polyphonicSnippet.FrontPaddedSnippet ...>
'''
if self.rowvalues[snippetPosition].strip() != "":
thisBlock = self.rowvalues[snippetPosition:snippetPosition + 5]
if thisBlock[4].strip() == "":
if self.timeSigBegin == "":
return None ## need a timesig
thisBlock[4] = self.timeSigBegin
blockOut = self.convertBlockToStreams(thisBlock)
if snippetType == 'begin':
return polyphonicSnippet.Incipit(blockOut, self)
else:
return polyphonicSnippet.FrontPaddedSnippet(blockOut, self)