New in version 2.0.
True when note is both preceeded and followed by scalewise sibling notes. Otherwise false.
abjad> from abjad.tools import tonalitytools
abjad> t = Staff("c'8 d'8 e'8 f'8")
abjad> for note in t:
... print '%s\t%s' % (note, tonalitytools.is_passing_tone(note))
...
c'8 False
d'8 True
e'8 True
f'8 False
Return boolean.