Acid trance

Acid trance is a genre of trance music that emerged in the late 1980s, focusing on using the acid sound. The trademark sound of "acid" is produced with a Roland TB-303 by playing a sequenced melody while altering the instrument's filter cutoff frequency, resonance, envelope modulation, and accent controls. This real-time tone adjustment was not part of the instrument's original intended operation. Acid trance is the best known form of trance music in Belgium.