"Put John Van Deusen’s CD, “Yossarian,” into a disc player and you’ll hear polished, melodic songs reminiscent of Matchbox 20 or the piano-driven Ben Folds Five. It’s hard to believe that the mature songs, intricate piano performances and deep, comforting voice were all produced by a 17-year-old high school student. The burgeoning talent of Van Deusen, now 18, has been recognized by Experience Music Project, which selected him and his band as finalists in Sound Off, a competition for regional bands aged 21 or younger.