Trumpeter Paul Smoker, Iowa's resident new-jazz genius, has made several trips to Chicago in recent years, and if you've never heard him, you've been missing one of the most coherent improvisers in music today. (And that's not even mentioning his technique--I can think of no modern trumpeter who could beat this guy in a cutting contest). But without slighting Smoker, I must shout even louder about Borah Bergman, the virtually unknown pianist making his Chicago debut this weekend. Bergman refuses to be bound by conventions of any kind, even those that have accrued in "free jazz," the term that most nearly describes his music; such conventions, which derive largely from the cryptic and episodic forays of Cecil Taylor, are nowhere to be found in Bergman's wide-ranging, superhuman virtuosity. (One indication of Bergman's rigorous iconoclasm: he used to study music's universality, and its concomitant potential for synthesis, by listening simultaneously to recordings of Karlheinz Stockhausen and Erroll Garner.) Together, Bergman and Smoker create music that is kinetic, uncompromised, and pure freedom: very demanding music of an exceptionally high order. Friday's duo performance will be preceded by a solo set from Smoker; on Saturday, it's Bergman's turn to present the curtain raiser. Tonight and Saturday, 8 PM, Southend Musicworks, 1313 S. Wabash; 939-2848.