Transposing in modes??

[Nathan Finch]

I was wondering if there is the capacity to transpose to a different
mode, or a way to shift a passage of notes diatonicly (or
chromatically). Basically (in version 2.6.5) if I have a set of notes,
"riff = { c8 e g b a g f e }", and want to create a sequence out of
that riff, so that I get something like "sequence = { c8 e g b a g f e
|  d8 f a c b a g f  |  e8 g b d c b a g | ... }", it would be nice to
"sequence ={ \riff
\transpose c d \dorian \riff
\transpose c e \phrygian \riff
\transpose c f \lydian \riff
...
}" to obtain the same results. There are possibly more uses for this,
such as "minor-ifying" pieces, but this would really shine in creating
sequences (for repeditive stuff that shifts around, and especially in
creating practice sheets with scale variations). I suppose you would
encounter problems with accidentals and octave placement, but I'm sure
there are creative ways around this. I think this would be a cool
feature, and have seen questions like this (but were very old, like
version 1.4.x), but did not pertain to lilypond as it stands today. I
am a musician and can code a bit , and would love some help in
undertaking something like this. Hopefully this can benefit the
lilypond and its community as a whole.

-Nathan