New in version 1.1.1.
Convert int, long or float number and letter in ['c', 'd', 'e', 'f', 'g', 'a', 'b'] to unique pair of one-character accidental string and integer octave number.
abjad> pitchtools.number_letter_to_accidental_octave(14, 'c')
('ss', 5)
abjad> pitchtools.number_letter_to_accidental_octave(14, 'd')
('', 5)
abjad> pitchtools.number_letter_to_accidental_octave(14, 'e')
('ff', 5)