A fine soloist with a distinctive sound not overly influenced by J.J. Johnson, Jimmy Knepper's improvisations are full of subtle surprises. He began on trombone when he was nine, started playing professionally when he was 15, and worked in the big bands of Freddie Slack (1947), Roy Porter (1948-1949), Charlie Spivak (1950-1951), Charlie Barnet (1951), Woody Herman, and Claude Thornhill. Knepper gained fame for his versatile and inventive playing with several of Charles Mingus' groups (1957-1962). He also worked with Stan Kenton (1959), Herbie Mann (a 1960 tour of Africa), Gil Evans, Benny Goodman (a 1962 tour of the Soviet Union), and the Thad Jones/Mel Lewis Orchestra (1968-1974), in addition to playing in the 1970s with the Lee Konitz Nonet and Mingus Dynasty. Knepper's reputation in the jazz world has remained quite strong, although he has not recorded that often as a leader, cutting sessions for Debut, Bethlehem (both in 1957), SteepleChase (1976), Inner City, Blackhawk, Hep, Soul Note, and Criss Cross.

During the '80s and '90s, Knepper could most often be found touring Europe, gigging frequently and occasionally recording, an ever vibrant gun for hire. He also remained an active member of the Mingus Dynasty, anchoring the trombone section with his distinctive tone and solos much as he had during his two brief tenures with Mingus in the early-'60s and mid-'70s. Diagnosed with Parkinson's in the '00s, Knepper's pace slowed considerably and on June 14, 2003 he passed away due to complications from the disease.

Scott Yanow -All Music Guide