Name of a chord member by its interval above the root (12-TET semitones, as in
CHORD_FORMULAS): 'R', 'b3', '3', '5', 'b7', '7', '9', '#11', '13'…
Ninths, elevenths and thirteenths are named as such when the formula writes them above
the octave (14 = '9'); below it they are '2', '4', '6' (sus2, sus4, sixth chords).
The rest of the formula decides two cases: 9 semitones is 'bb7' in a diminished seventh
chord, and 3 semitones is '#9' beside a major third.
Parameters
interval: number
Semitones above the root (0-23; larger values are reduced by octaves).
Name of a chord member by its interval above the root (12-TET semitones, as in
CHORD_FORMULAS):'R','b3','3','5','b7','7','9','#11','13'… Ninths, elevenths and thirteenths are named as such when the formula writes them above the octave (14 ='9'); below it they are'2','4','6'(sus2, sus4, sixth chords). The rest of the formula decides two cases: 9 semitones is'bb7'in a diminished seventh chord, and 3 semitones is'#9'beside a major third.