[1] He has worked with John Mayall, Frank Zappa, Jeff Beck, Journey, Jefferson Starship, Nils Lofgren, Eric Burdon, Shuggie Otis, Ian Hunter, Lou Reed, David Bowie, Mick Ronson, Whitesnake, Pat Travers, Sammy Hagar, Michael Schenker, UFO, Michael Chapman, Jake E. Lee, Leslie West, Kathi McDonald, Keith Emerson, Mike Onesko, Herbie Mann and Flo & Eddie.

Subsequently, Dunbar founded a short-lived progressive rock band called Blue Whale, which debuted with a tour of Scandinavia in January 1970.

[1] Following the recent collapse of the original lineup of King Crimson, Dunbar unsuccessfully tried to recruit Robert Fripp as Blue Whale's guitarist.

In the mid-1970s Dunbar played drums for former Grin leader, Nils Lofgren, before joining the newly formed Journey on February 1, 1974.

He remained a member until the end of the Infinity Tour on September 2, 1978 in Oakland, a period that encompassed Journey’s first four studio albums.

In 2008 Dunbar recorded an album of material for Direct Music with Mickey Thomas of Starship, and musicians such as Jake E. Lee, former guitarist for Ozzy Osbourne.

The complete recordings of Dunbar's drumming with Frank Zappa at Carnegie Hall in October 1971 were released exactly 40 years after the event in a four-CD set.