Keen on jazz, Reeves played in the New Jazz Orchestra and had learned many standard songs. He worked in the music industry for several years, first in the quality control department of Decca Records listening to output that ranged from medieval classical music to Chubby Checker, after four years becoming assistant producer to Tony D'Amato, then briefly a record plugger for Pye Records. In late 1964 he suggested for Pye release, and played on, the instrumental UK hit Sounds Orchestral's "Cast Your Fate to the Wind". He became assistant to Tony Hatch at Pye before leaving to become a freelance producer for CBS and Polydor and creative director of the Greenwich Gramophone Company. He also recorded with The Mike Taylor Quartet on the album Pendulum in 1965 and with Davy Graham on Folk, Blues and Beyond and Midnight Man in 1966.
Shortly afterwards he took up electric bass, just before Hiseman recommended him to Mayall. After two albums with Colosseum he left to concentrate on session work and production, working with the Woods Band, Sandy Denny (The North Star Grassman and the Ravens), Paul Kent, John Martyn (Bless the Weather), Day of Phoenix and Burning Red Ivanhoe from Denmark, and Chris DeBurgh. In 1972 he rejoined Dave Greenslade and formed the band Greenslade. Reeves remained with the band until 1974, recording three albums with them. Subsequently he played with Curved Air and in jazz band called Big Chief, with former Colosseum saxophonist Dick Heckstall-Smith. He still plays with Big Chief, Blue Amba and The Warthogs, and plays double bass at The Constitution pub in Camden Town (Davy Graham's local) every other Tuesday in the Cellar Bar.