Anyway, it shouldn't be all that far-fetched to those of you
out there who know and love Ranma... if Rumiko-megami
can make a martial art out such things as gymnastics and
speed-eating, why not music?

Itsu mo,
Ucchan   ^_^

I can't believe you suggested this. I mean there's already too much sax
and violins in anime as it is. You're just prolonging the stereotype.
But seriously... this could be really neat. There could be multiple
schools of musical combat...

Musical Ninjitsu- Strangling people with guitar strings, concealed
flutes

Sumo Tuba or alternatively Sumo Bass Drum... something like that...

It might be neat to throw in guest appearances by the Violinist of
Hamelin cast, or perhaps Minmei... REBA WEST!!! (everyone but me cringes
in terror as she picks up her microphone and sings the classic Robotech
theme We Will Win!).
Or perhaps a Jazz free form style that specializes on making things up
on the spot... 
seems like a style Ranma could identify with.
Or a classical music style with lots of pre-preparation (Mousse seems to
fit this bill).
Just some thoughts.
 -Tin