Invented in Chicago’s black, working-class communities in the mid ‘80s, the first house productions represented disco writ small, with newly affordable synths and drum machines in place of a full band. It was the Roland TB-303 bass synth that set acid house apart. The style was born when the pioneering Phuture began fiddling with knobs and came up with the genre’s mind-bending hallmark, an undulating squeal that sounded like nothing before (or since). Acid was soon everywhere in Chicago, particularly on labels like the landmark Trax, which specialised in minimalist funk at its most devastating. In the UK, acid house took root in rave’s muddy fields, flowering into the psychedelic crossover dance of acts like Orbital and Primal Scream. Decades later, acid hasn’t lost its bite; its gurgling frequencies cut through underground clubs around the world. Season after season, it remains one of dance music’s most enduring styles.