microtonal music
Music that uses intervals smaller than the standard Western semitone, exploring the pitch spaces between the notes of the twelve-tone equal temperament system.
In Depth
Microtonal music divides the octave into more than 12 equal parts, or uses non-equal divisions based on natural harmonic ratios. While Western music settled on 12-tone equal temperament by the 18th century, many world traditions — Arabic maqam, Turkish makam, Indian raga, Indonesian gamelan — have always used microtonal intervals. Western interest in microtonality dates to the early 20th century, with composers like Charles Ives, Alois Hába, and Julian Carrillo experimenting with quarter-tones and smaller divisions.
Harry Partch built an entire orchestra of custom instruments tuned to a 43-tone just intonation scale. Ben Johnston composed string quartets using intricate just intonation systems. More recently, electronic music has made microtonal composition more accessible — Aphex Twin, Sevish, and King Gizzard & the Lizard Wizard have all explored microtonal tuning. The 2010s saw a microtonal renaissance, with instruments like the Lumatone keyboard making alternative tunings practical for live performance.
Harry Partch was so committed to microtonal music that he built over 30 custom instruments from scratch, including the Cloud Chamber Bowls made from Pyrex carboys salvaged from a nuclear physics lab.