22ET

22ET, also written as 22-ET or 22EDO, refers to a tuning system that divides the octave into 22 equal steps. In this system, each step advances by 1200/22 ≈ 54.545 cents, yielding 22 distinct pitch classes per octave. As an equal temperament, 22ET preserves the octave equivalence while distributing pitches more finely than the common 12-tone equal temperament.

Structure and notation: The chromatic collection consists of 22 evenly spaced pitches within each octave. Pitch classes are typically labeled with microtonal accidentals or numerical step indices. Because 22 is not divisible into the standard diatonic pattern, scales built in 22ET often require new collections of intervals and may be used with microtonal keyboards or software tunings that support 22EDO.

Interval relationships: As with other ET systems, intervals in 22ET are defined by step counts. Some well-known just intervals are approximated: a major third is near 7 steps (about 381.8 cents versus 386.3), and a perfect fifth near 13 steps (about 708.1 cents versus 701.96). The larger step size yields distinct temperaments compared with 12TET, producing characteristic sonic textures used in microtonal music.

Historical and contemporary use: 22ET has appeared in theoretical discussions and experimental music as a means to explore alternative tonal landscapes. It is not part of standard Western music practice, but it is supported by many digital audio workstations, synthesizers, and dedicated microtonal keyboards that implement 22EDO tunings. Researchers and composers study 22ET to investigate scale construction, harmony, and voice-leading in finer tonal subdivisions than 12TET provides.