New in version 1.1.
True when arg has the form of a chromatic pitch-class / octave number pair. Otherwise false:
abjad> pitchtools.is_chromatic_pitch_class_name_octave_number_pair(('cs', 5))
True
Return boolean.
Changed in version 2.0: renamed pitchtools.is_pair() to pitchtools.is_chromatic_pitch_class_name_octave_number_pair().