 He was also a prolific session musician and worked with the Who on the film soundtrack of "Tommy", Joe Cocker, Traffic, George Harrison, Jerry Lee Lewis, Peter Frampton, the Bee Gees's Maurice Gibb, Gary Wright, Johnny Thunders, Luther Grosvenor, Neil Innes, Steve Gibbons, Chris Jagger, Nanette Workman, Sean Tyla, Jim Capaldi, Pat Travers and Andy Fraser.In 2014, Kellie released his debut solo album "Music from The Hidden", while still a member of the Only Ones.He died on 18 January 2017 following a short illness.