At age 17, Barron Collier High School junior Chris Sochor has written a jazz concerto, a piano suite and any number of shorter pieces bubbling up from his music-steeped mind. He's about to have something only a few composers his age get, however: hearing it performed for an audience by a jazz orchestra. The premiere is this Sunday at Artis—Naples. Not that Chris will have the luxury of enjoying it from the audience — he's the featured pianist in the Concerto of the Unheard, which the Naples Youth Jazz Orchestra performs in concert. (For tickets, see the information box with this story.)