Keith Knudsen (1948-2009) was an American drummer and vocalist best known for his work with the rock band The Doobie Brothers. He joined the band in 1974, contributing to their signature sound during a pivotal period when they achieved commercial success. Knudsen's drumming style combined rock with elements of rhythm and blues, which was a hallmark of The Doobie Brothers' music. Notable works featuring Knudsen include the albums "Stampede" (1975), "Takin' It to the Streets" (1976), and "Livin' on the Fault Line" (1977). His vocal contributions can be heard on tracks like "Black Water," where he provided harmonies that enriched the band's sound. Beyond his time with The Doobie Brothers, Knudsen was involved in various musical projects, including collaborations with other artists and participation in reunion tours. His impact on music is highlighted by his role in the evolution of the band's sound, which blended rock, pop, and R&B influences, helping to shape the sound of the 1970s. Knudsen’s musicianship remains recognized among fans of classic rock and has influenced subsequent generations of drummers.