- because I don’t want to compose a separate bass line that’s independent of the chord notation.
The purpose is aiding the choice of inverted chords that already have the appropriate bass note in them. This leads to (much) better-sounding music. This has actually been my biggest take-away from the two hooktheory books (thanks!)
Being able to clearly see the bass notes of the chords in the display, would greatly help users spot any bass leaps that suggest that a better chord inversion could be found.
In terms of implementation, you could have one main button (next to “Piano” for example) that toggles the display of the bass part (and only the bass part) temporarily replacing the melody. Alternatively it could be a tickbox in the “Voice Management” options for melody. Those are just two suggestions but there are probably a number of simple ways to do this which also do not complicate the UI.