Gerald Rydel Simpson, better known as A Guy Called Gerald, is a British record producer and musician. He was an early member of the electronic group 808 State, contributing to their debut LP Newbuild (1988) and hit single "Pacific State" (1989). He also achieved solo success with his 1988 hit single "Voodoo Ray", which became a touchstone of Manchester's acid house scene and reached No. 12 in the UK charts. He embraced breakbeat production in the 1990s, with his 1995 album Black Secret Technology becoming a "much-touted candidate for 'best jungle album ever.'" He also ran the London-based independent record label Juice Box Records from 1991 to 1998.

808 State are an English electronic music group formed in 1987 in Manchester, taking their name from the Roland TR-808 drum machine. They were formed by Graham Massey, Martin Price and Gerald Simpson. They released their debut album, Newbuild, in September 1988 and secured commercial success in 1989, when their song "Pacific State" was picked up by BBC Radio 1 DJ Gary Davies and charted for 11 weeks in the UK.