pub fn convert_diatonic_number_to_step(dn: IntegerType) -> (char, IntegerType)Expand description
The step letter and octave of a diatonic note number, counting C0 as
1: music21’s convertDiatonicNumberToStep, so 15 is C in octave
2, 0 is B in octave -1, and -19 is D in octave -3.