Cellist GABRIEL JELLEN played the violin and the clarinet as a boy, and he enjoys playing alto and tenor saxophone in his free time. But his passion is playing the cello. From his early years in the Bronx he was fascinated when he listened to the practicing of a New York Philharmonic cellist who lived in the same building. His mother decreed, however, that Gaby was too small for such a large instrument, and he was handed a violin. After moving to California, he became a member of Peter Meremblums youth orchestra (initially as a violinist, later rejoining as a cellist). The young musician was hired to play in an MGM film starring Robert Taylor. After he renewed his love affair with the cello, Jellens teachers included Gregory Aller and Kurt Reher, the Philharmonics former Principal Cellist. His first professional job was in the cello section of the Stan Kenton Orchestra, but he soon found his way to the post of Assistant Principal Cello in the Tulsa Philharmonic. It was ten years later (after serving with the Saint Louis Symphony and the New Orleans Philharmonic) that he joined the Los Angeles Philharmonic in August 1963. His first season was in the old Philharmonic Auditorium, where he had listened as a child to concerts conducted by Albert Coates and Alfred Wallenstein.