Acid house is a spawn of house music which generally utilizes the structure of its predecessor, and emphasizes a repetitive, hypnotic and trance-like style, often with samples or spoken lines rather than sung lyrics. Acid house instrumentation typically consists of analog synthesizers (predominantly the Roland TB-303), 4/4 beats, pop vocals enhanced with a large amount of echo and reverb, symphonic choirs, claves loops, and in many cases, effects similar to radio tuning. Acid house is often played at clubs and raves, and has also spawned acid house parties. The Chicago-based group Phuture are typically considered the pioneers of the genre.
Acid house spread to the United Kingdom and continental Europe, where it was played by DJs in the acid house and later rave scenes. By the late 1980s, copycat tracks and acid house remixes brought the style into the mainstream, where it had some influence on pop and dance styles.
Acid house has also spawned the subgenres acid techno, acid Trance, acid rock and acid jazz. Related genres include acid rap and trip-hop . Nicknamed "the sound of acid", acid house's influence on dance music is tangible considering the sheer number of electronic music tracks referencing acid house through the use of its sounds, including trance, Goa Trance, psytrance, breakbeat, big beat, techno, trip-hop and house music.