Reprinted from yesterday's late editions.

What you're supposed to want, if you're a jazz musician, is to Become A Legend - and almost anyone can tell you that Herbie Hancock and Chick Corea blew their chances to do that quite a while ago.

To Become A Jazz Legend, it is almost mandatory that you die young, neglected and broke, because only 17 people in the world understood what you were doing when you were doing it.

Corea and Hancock are still young enough to Become Legends, but they have made too much moeny and for long stretches in both of their careers nearly everyone has understood what they were up to.

It's been a long, roundabout road to the point where these two musicians set their pianos (acoustic pianos, you have to specify at this stage in the development of the musical art) side by side on the same stage, with no horns or rhythm section or any of the other usual supports available for a jazz pianist.

Wednesday's musical adventre included one piece that was wholly and jointly improvised on the spot, and it was a complete success with the audience. It included atonal sections and passages where one player reached his hand into the piano's guts for the direct contact with the strings in the avant-garde manner. There were Bartok-style motor rhythms, free melodic and harmonic excursion, and a range or color, feeling and style from shy, tentative whispers to great, crashing chords. It worked.

There was improvisation within a more traditional jazz framework in all the other pieces they played except for one piano duet from Bartok's "Mikrokosmos," which had surely never before been played on the same program with improvisations on "Some Day My Prince Will Come" and Gershwin's "Liza."

Both players were technically excellent and (after a week's intensive rehearsals) they played with almost intuitive coordination.

At this point, it is clear that Corea and Hancock are both engaged in bringing a mass audience along into areas of music which had been strange to them. In the interview, Corea estimated that 60 to 70 percent of his fans had come to his music from areas other than classical and jazz, and Hancock thought that the percentage among his fans might be as high as 80.