In the mid-30s Benny Goodman became music's first crossover phenonmenon, moving impressively from jazz to the classical staple. He later credited his success to basic training in "classical" techniques in Chicago, where he was born in 1909. The King of Swing's debut as a classical clarinetist, with the venerable Budapest String Quartet, resulted in a noteworthy recording of the Mozart Clarinet Quintet. An even more lasting achievement, however, was the 1938 piece written for Goodman by Bartok. Contrasts, for clarinet, biolin, and piano, is a landmark work that deftly tailors jazz's syncopated rhythms and penchant for improvisation to classical's more rigorous confines; it won critical praise for its Carnegie Hall debut (performed by Goodman, violinist Josef Szegeti, and Bartok himself at the piano). In this Chicago Chamber Musicians concert, the piece will be performed by the talented Larry Combs, the CSO's principal clarinetist and a jazz aficionado; his accomplices are Deborah Sobol (piano) and Joseph Gensuldi. Combs will also strut his stuff in Morton Gould's homage Benny's Gig; unfortunately, rounding out the program is Beethoven's Septet for Winds and String, a pleasantly insipid distraction that shows even great composers can occasionally stumble. A Goodman salute precedes the concert at 6:30 featuring Combs and pianist Larry Novak in a medley of Goodman tunes, including "Goodbye," his closing signature. Sunday at 7:30 PM, Pick-Staiger Concert Hall, Northwestern University, 1977 Sheridan, Evanston; Monday at 7:30 PM, concert hall, DePaul University, 800 W. Belden; 973-4513.