Knudsen was born in Le Mars, Iowa. He began drumming while attending
Princeton High School in Princeton, Illinois, where he graduated in 1966. After short stints playing in a club band and the Blind Joe Mendlebaum Blues Band, he became the drummer for
organist/vocalist
Lee Michaels. He played in The Hoodoo Rhythm Devils from late 1972 through mid 1973. He never participated in any formal studio recording with them, but recorded a live Texas Special on KSAN-FM in San Francisco with the Hoodoos and Johnny Winter. His big break came in 1974 when he was invited to join
The Doobie Brothers, replacing the departing
Michael Hossack. Knudsen joined the band during the recording of the 1974 Top 10 platinum album,
What Were Once Vices Are Now Habits. He made his recording debut with the Doobies on that album in 1974, performing
backing vocals over instrumental tracks that included Hossack. Knudsen did not get behind the drum kit in the recording studio until
Stampede in 1975. Knudsen was co-drummer with
John Hartman, (and later, Chet McCracken) until the Doobies disbanded in 1982. His contribution to the group's vocal harmonies in the studio and in concert was as crucial as his drumming. After the Doobies disbanded in 1982, Knudsen and fellow Doobie
John McFee formed the
country rock band
Southern Pacific. The group was successful in the country charts but disbanded in the early 1990s. By then, the two men had formed a writing partnership and despite not rejoining the group at that time, co-wrote the song
Time Is Here And Gone with Doobies' percussionist
Bobby LaKind, featured on the Doobies reunion album
Cycles in 1989. Knudsen organized a one-off Doobies reunion in 1987 to raise funds for the
National Veterans Foundation. After Southern Pacific folded, both he and McFee rejoined the Doobie Brothers on a full-time basis in 1993. Ironically, Knudsen found himself drumming alongside Michael Hossack, whom he had once replaced. Of the multiple pairings of Doobie Brothers drummers over the decades, Knudsen's partnership with Hossack lasted the longest. He featured prominently as a songwriter on the album
Sibling Rivalry (2000). He also featured on the albums ''
Rockin' Down the Highway: The Wildlife Concert (1996), and Live at Wolf Trap (2004). In 2005, he played drums on Emmylou Harris "Shores Of White Sand" off her All I Intend To Be'' album. Though Knudsen was a frequent backing vocalist for the Doobie Brothers, he did not sing lead on many released Doobies tracks. On "Double Dealin' Four Flusher" (from
Stampede) he is heard trading brief lead vocal lines with Pat Simmons and Tom Johnston. (The box set ''Long Train Runnin': 1970–2000'' has an early rehearsal version of this song, called "Shuffle," with vocals only by Simmons and Knudsen.) Knudsen can also be heard singing lead on songs from the 1982 Doobie Brothers Farewell Tour ("Don't Start Me To Talkin'" from
Farewell Tour; "Listen To The Music" from
Live at the Greek Theatre 1982).
Sibling Rivalry features two later, and very different sounding, Knudsen lead vocals. Knudsen died of
pneumonia at a rehabilitation hospital in Kentfield, California, at the age of 56. He was living in
Sonoma County with his wife, artist Kate Knudsen, and his daughter, Dayna Keyes, a radio disc jockey and voiceover actor, at the time of his death. ==Discography==