Well-tempered
Well-tempered denotes tunings in which all keys sound usable without all semitones being equal. The term is known through Bach's “Well-Tempered Clavier”. It does not mean equal temperament here, but an unevenly distributed temperament.
- Meaning
- all keys playable, each with its own character
- Not the same
- equal temperament (twelve equal semitones)
- Best-known work
- Bach, The Well-Tempered Clavier (1722 and 1742)
- Counterpart
- meantone tuning with a wolf fifth
All keys, but not all alike
On the page Circle of fifths it says: Johann Sebastian Bach championed the new well-tempered tunings by writing, with the “Well-Tempered Clavier” (1722 and 1742), a prelude and a fugue in each of the 24 major and minor keys. He wanted to show that every key was now musically playable on a single instrument. “Well-tempered” did not mean equal temperament, but tunings in which all keys sound usable.
| Tuning | Feature according to the article on tuning | Consequence |
|---|---|---|
| Just intonation | intervals of one key exactly pure | flawless in one key, modulation unbearable |
| Meantone | thirds pure, fifths somewhat smaller | warm, but a “wolf fifth”, some pieces not playable |
| Well-tempered | unevenly distributed temperament | all keys playable, each with its own character |
| Equal-tempered | all semitones equal | all keys equally good and equally imperfect |
The article Equal, meantone, just: why your piano is slightly out of tune takes the point further: Bach's work covers all 24 keys, which would have been impossible on a meantone-tuned instrument. “Well-tempered” explicitly does not mean “equal-tempered” but an unevenly distributed temperament in which all keys are playable but each keeps a character of its own. That B♭ major sounds different from B major was audible to Bach's audience.
Why it became necessary
The reason is the Pythagorean comma: twelve pure fifths exceed seven octaves by about 23 cents. Every tuning has to put this error somewhere. Meantone temperament, according to the article, makes the major thirds pure and shrinks every fifth a little, with the consequence of a single, dreadfully out-of-tune wolf fifth. Equal temperament distributes the comma completely evenly, standard since the 19th century. See Pythagorean comma and Just intonation.
Common mistakes
- Equating well-tempered and equal-tempered: Well-tempered means an uneven distribution in which each key keeps its character.
- Assuming Bach's keyboards were tuned in equal temperament: According to the article “well-tempered” explicitly does not mean “equal-tempered”.
- Dismissing the differences between keys as imagination: Bach's audience heard them on well-tempered instruments.
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Related terms
Just intonationPythagorean commaCircle of fifthsCentStandard pitchEnharmonic equivalenceIntonation
Editor: Maik Krohm · reviewed on 3 October 2026
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