Acid house

A subgenre of house music that emerged in Chicago in the mid-1980s, defined by the squelching, resonant bass lines of the Roland TB-303 synthesizer, paired with drum-machine beats (often from the Roland TR-808 or TR-909). Phuture’s “Acid Tracks” (1987) is usually credited as the first acid house record. The style spread to the UK in 1987–88, where it fuelled the “Second Summer of Love”, the rave and warehouse-party scene, and the smiley-face iconography associated with it. It went on to influence later electronic genres such as acid techno and trance.