New in version 2.0.
True when notes in expr are scalar.
abjad> from abjad.tools import tonalitytools
abjad> t = Staff("c'8 d'8 e'8 f'8")
abjad> tonalitytools.are_scalar_notes(t[:])
True
Otherwise false.
abjad> tonalitytools.are_scalar_notes(Note("c'4"), Note("c'4"))
False
Changed in version 2.0: renamed tonalitytools.are_scalar() to tonalitytools.are_scalar_notes().