Joachim Chassman, 88, a Los Angeles violinist who was a featured soloist with many area groups, including the orchestras for CBS Radio, 20th Century Fox, Columbia Pictures and the Santa Monica Symphony. He and Oscar Wasserberger performed the West Coast premiere of Prokofiev's "Sonata for Two Violins." Chassman was a concertmaster and chamber music soloist for more than 50 years. He was given a Life Achievement Award by the American String Teachers Assn. and was a former president of Arts and Artists Inc. In Sherman Oaks on Jan. 21.