Roman Numerals
Numeral
About
A figure is figured bass over a scale degree:
V7, ii65,
viio7/V, It6,
Ger65, N6,
Cad64, I[no3],
V7[add4]. Uppercase is major, lowercase
minor; a key written lowercase is minor.
Naming a chord is music21's
romanNumeralFromChord: every altered
degree is written into the figure, so a diminished
triad on the tonic of C major is
io5b3 and an augmented sixth is named
as one. Leave the key empty to read the chord in
its own root.