31 Tone Equal Temperament (31-ET) is a tuning system or scale consisting of 31 equal divisions of the octave.

- Notation
- Enharmonic Equivalents
- 34 Tone Equal Temperament
- Quarter Tones
- Why 31 Tone Equal Temperament?
- Cycles
- Consonance
- Just Intonation
- Harmonic Context
- Harmonic Strength
- 22 Tone Equal Temperament
- 19 Tone Equal Temperament
- Tempering Out
- Distinguishing Intervals
- Tone Clusters
- Harmonic Series
- Xenharmonic
- Equal Temperament
- Meantone Tuning
- 41 Tone Equal Temperament
- Microtonality and Microtonal Music
- 17 Tone Equal Temperament
- 53 Tone Equal Temperament
- The 13th Harmonic and 31-ET
- Harmonic Ambiguity

Wikipedia currently has a good article about 31 tone equal temperament.

About 31-Tone Equal Temperament - Paul Rapoport's resource on this tuning. (1987)