Acid house is a variant of house music characterized by the use of simple tone generators with tempo-controlled resonant filters. It began when musicians discovered that they could create interesting sounds with the Roland TB-303 analogue bass synthesizer by tweaking the resonant frequency dial as they played.
Phuture - Chicago-based group of acid house pioneers, formed in 1985, and best known for their classic 1987 single "Acid Tracks", which defined the genre
808 State - British outfit from Manchester, formed in 1989. Their first album, Newbuild, was acid house, and occasional acid house influences appeared in later tracks.