umm, it's jazz but...
Have you heard Keith Jarrett? Piano, original melodies, no vocals (well, not intentional at least). Some of the best music - not just piano music - ever played, recorded or heard.
Bill Evans? Erroll Garner? Oscar Peterson?
All artists mentioned have recorded solo sets; worth a listen. As far as I know (and please correct me) most solo piano without vocals is either jazz or classical.
Or you could come and hear me bang the keys after a few drinks (saving grace: I don't sing - don't hum... actually I barely even play).
NADishman
(post #2 - hello everybody)