Suggestion for diatonic chordRootNames function

[Johannes Asal]

Hi,

I am writing a music theory book about jazz harmonics. To do this properly one
needs a possibility to describe diatonic chords with appropriate symbols like
Imaj7, IIm7, IIIm7 etc. It seems that this is not yet supported in Lilypond. I
took a look at the source code and found the Scheme function chordRootNames that
seems to be responsible for selecting the symbols for chord roots. It should be
easy to add another function, that follows the diatonic naming convention. The
only problem I see is that you would need one or two additional parameters for
the scale root and modus so that the function knows what 'harmonic function' it
is and whether it is altered or not (something like bII7 for Db7 in C ionian).

I hope it is clear, what I am suggesting. I would have implemented it myself if
it was C++, but my Scheme skills are unfortunately not high enough.

Best regards,
Johannes Asal