Longtime Doobie Brothers drummer Keith Knudsen has died of pneumonia in the US at the age of 56.
Keith Knudsen (centre) joined the Doobie Brothers in 1974
Having joined the band in 1974, he enjoyed hits with Taking it to the Streets and Black Water.
Although the band split in 1982 following a farewell tour, they later came back together and began extensively touring.
"We're going to miss him on drums. I'm going to miss him as a buddy." said the band's founder Tom Johnston.
Knudsen, who lived in Sonoma County, California, had been in hospital for about a month.
"I just saw him Sunday, just before the Super Bowl. "He was in good spirits. He was weak, but he was OK," the band's longtime manager Bruce Cohn said.
Exciting live act
Knudsen had undergone treatment for cancer in 1995.
"It left him weak and I don't think he ever fully regained all his strength," Johnston said.
The Doobie Brothers were known for mixing blues and gospel with rock music and had a reputation as an exciting live band.
While the Doobie Brothers were on hiatus, Knudsen and bandmate John McFee formed the country rock group Southern Pacific, recording four albums together.
The Doobie Brothers had a number of line-up changes through the years, but in 1992 all 12 previous members came together to for two charity concerts.
Money raised went to a trust fund for the children of percussionist Bobby LaKind, who had been diagnosed with terminal cancer. He died later that year.
After the Doobie Brothers reformed, they had two top UK 40 hits with Long Train Running in 1993 followed by a remix of their biggest hit Listen to the Music in 1994.