Examples of pianos used in non-diatonic music?

Also, are tone clusters ever a good substitute for microtonal variations? Pros/cons of both?

Last night I was listening to a CD of Arabic piano music, "Le Piano Dans La Musique Arabe" (possibly out of print now). As far as I know, a normal piano cannot produce microtones. The last few tracks on this CD were recordings of a specially modified piano with additional pedals that allow for microtones. However, I have seen some claims that, for example, Sun Ra was able to obtain such microtones when he played. I can't remember where I read this, probably in the liner notes of one of the Evidence reissues of his work.

I thought I read somewhere that tone clusters have no distinct pitch. You may hear the highest or lowest note being played, combined with a variety of dissonances, but this doesn't seem at all a basis for scalar melody. Pro: it would never be folk music. Con: it would never be folk music.

Though in a way, aren't tone clusters (perhaps this is an incorrect use of the term) sort of the basis of the Ornette Coleman approach? The melodies are sometimes based on tone clusters constructed from separate, monophonic instruments (esp. when they are playing in different keys). Perhaps when they are played by different instruments the tonal interactions are more distinct? At least that's how I hear it. I don't know anything about the physics of sound though.

Do you mean "non-prepared piano" to exclude pianos that are simply *tuned* differently than usual? Because if not, then certainly you can just have the piano retuned to whatever temperament you prefer-- Ben Johnston and Lou Harrison (they're not jazz people) have piano music that is non-western-tempered.

Of course, this poses major problems for improvised musics (you have to retune it every time you change keys, or overtone series), but I don't see why that would affect the piano's future in jazz.

What is 'diatonic music'?

'diatonic adj 1: (music) based on the standard major or minor scales consisting of 5 tones and 2 semitones without modulation by accidentals [ant: chromatic] 2: based on or using the five tones and two semitones of the major or minor scales of Western music'

For these purposes let's include 'chromatic' (12-tone) as well, as long as there's ONLY those ones!

I'm afraid I don't understand that. I didn't know you were so "technical", Q.

What I mean is, on a gtr, sax, violin etc you can make any note slightly flat or sharp while you're playing, so if you want to use certain non-Western scales you can do it, whereas with a piano you can't, because one key=one fixed tone.