Official band members
● Alan Parsons – production, engineering, programming, composition, keyboards, guitar
● Eric Woolfson – composition, lyrics, piano, keyboards, vocals, executive production

Notable contributors
● Andrew Powell – composition, keyboards, orchestral arrangements (1975-1990)
● Philharmonia Orchestra
● The English Chorale – choir (1976, 1977, 1982, 1987)
● Ian Bairnson – guitar (1975–1990)
● David Pack – guitar (1976)
● David Paton – bass, vocals (1975–1985)
● Duncan Mackay – keyboards (1977–1979)
● Richard Cottle – keyboards, saxophone (1984–1990)
● Laurence Cottle – bass (1987-1990)
● Stuart Tosh – drums, percussion (1975–1976)
● Stuart Elliott – drums, percussion (1977–1990)
● John Leach – cimbalom, kantele (1976–1978)
● Colin Blunstone – vocals (1978–1984)
● Chris Rainbow – vocals (1979–1990)
● Lenny Zakatek – vocals (1977–1987)
● John Miles – vocals (1976, 1978, 1985, 1987)
● Jack Harris – vocals (1976–1978)
● Dave Townsend – vocals (1977, 1979)
● Elmer Gantry a.k.a. [a=Dave Terry (4)] – vocals (1980, 1982)
● Graham Dye – vocals (1985, 1990)

Non-recurring vocalists include: Arthur Brown (1975), Allan Clarke (1977), Peter Straker (1977), Jaki Whitren (1977), Dean Ford (1978), Clare Torry (1979), Lesley Duncan (1979), Gary Brooker (1985), Geoff Barradale (1987), Eric Stewart (1990)

Notable instruments: Projectron - A device built by Alan Parsons as an analog sample playback device, similar in general concept to a Mellotron. The Projectron consisted of a 24-track tape machine, with each playback channel routed to a voltage controlled amplifier; each VCA was in turn gated by a key of an attached keyboard. The device was used on the albums I Robot, Pyramid, and The Turn of a Friendly Card. But preparing tapes was a cumbersome process and the device was maintenance-intensive, so as soon as a Fairlight CMI became available to Parsons, he switched his sampling activities to that. Parsons scrapped the Projectron sometime after 1980, and no photos of it are known to have survived.