In early-’ 80s America, disco still ruled the dancefloor. Everywhere, that is, except Chicago. There, under the guidance of DJ Frankie Knuckles, a predominantly black gay club called the Warehouse had given its name to a tougher, more rhythmic style known simply as “house”. Yet when Knuckles left the club in 1982, it was Ron Hardy, resident DJ at Muzic Box, who pioneered the sound that inspired the UK’s acid house explosion at the end of the decade. Hardy would often include demo tapes in his mixes and in 1985 played an 11- minute instrumental created by local trio Phuture. A drum track embellished with a strange, “squelchy” synth riff, In Your Mind became a staple at the Muzic Box and was soon renamed “Ron Hardy’s Acid Track”. LSD was popular at the Muzic Box, but the psychedelic reference didn’t come from Phuture, who were all staunchly anti-drugs. Three young musicians from the suburbs, they’d been experimenting with a second-hand Roland TB- 303 bass synth. The mind-altering “acid” sound was an accidental overload caused when founder member DJ Pierre started twisting the knobs on the TB- 303 as it was playing. But its potential was obvious once heard over a club soundsystem. “People were going bananas,” he recalled later of its effect on the Muzic Box dancefloor. “It was surreal.” Re-recorded with producer Marshall Jefferson and released as Acid Tracks in 1987, Phuture hoped they might have a local hit: “We thought it was just popular in Chicago,” says Pierre. But across the Atlantic, their acid experiment was about to trigger the UK’s biggest youth culture revolution since punk.