Having started his musical career 1966-67 with the Wilde Flowers, he founded Caravan in 1968 with his cousin Richard Sinclair (bass/vocals), Pye Hastings (guitar/vocals), and Richard Coughlan (drums) and has been in and out of that band for 35 years (so far 1968-71, 1973–75, 1979–82, 1990–2002). On Caravan's first three albums, he developed his organ playing enormously until their famous album In the Land of Grey and Pink (1971). "Calyx, The Canterbury Website" even calls him "master of the typical Canterbury organ sound/playing" see "David Sinclair". Retrieved 2006-01-17.
Lately he has been engaged in a solo career, including concerts in Japan and two solo albums, Full Circle and Into the Sun (both 2003). A 30th anniversary re-release of his Moon Over Man album featuring vocalist Tim Lynk (demos for an unreleased solo album recorded 1976-77, originally issued on CD by Voiceprint in 1993) appeared in 2006 (including improved sound and bonus tracks), although this is due to be superseded by a further enhanced release of the same material. Two solo albums, PianoWorks1 - Frozen In Time and Stream (featuring several distinguished guest artists) are due for release early in 2011.