Lilypond of other programs will never be able to interpret notes as
chords (even humans can't do that because there are always ambiguities).
I think the more sensitive approach for pop and jazz is a chord
library with a string as input (maj7) and as output a notation as
markup for chord symbol, optionally as a realisation as notes or chord
diagram (could even have options to select or override the realisation).
That's what we have in essence with our current chordmode. The string has
some specific syntax, and it provides realization as notes, chord diagrams,
and chord names. But the chord names functionality isn't what we want right
The problem now is that you have to write the realization to get the chord name. Thinking the other way around is more logical from the composer point of view, in jazz at least. (or let the realization up to the interpreter).
So add me to the list of people who prefer chord names over chord tones!
You can find an example of a chord notated as 'phrygian' (well it's more a modal indication, but that's what the composer Gary Peacock intended) in the lead sheet for Vignette.
More arguments for using names: Alt is much more easy to write and read, less error prone than: 7.3-.5-.9-.11-.13-