The original composition of the band was a collection of session musicians brought together by Bruce Allen, manager of Loverboy. Drummer Jim Vallance and Bruce Fairbairn had a jazz rock band named Sunshyne. They incorporated Lindsey Mitchell and Ron Tabak, and switched names to "Under Construction" (also briefly "Stanley Screamer"). Then, when John Hall was brought in as keyboardist, the band's name became Prism.
After signing with GRT Records, they released their debut album with a lineup of Tabak, Mitchell, Lavin, Hall, Ab Bryant and Jim Vallance, who both produced, and played drums under the name of "Rodney Higgs." Vallance did not want to tour though, so left and was replaced by Rocket Norton.
In 1977, they released their self-titled album PRISM, and it had a hit with "Spaceship Superstar". The band subsequently issued See Forever Eyes (1978), after which Bryant left, and Allen Harlow was brought in as a new guitarist.