welltempering

Well tempering (often written well-tempering or well temperament) refers to a family of musical tuning systems developed in the 17th and 18th centuries that permit music to be played in all keys while retaining distinct key characters. Unlike equal temperament, which divides the octave into twelve equal semitones, well temperaments distribute slight, unequal adjustments across intervals so some keys sound more consonant and others more characterful. This preserves differences between keys that composers and listeners associated with particular moods or colors.

Well temperaments evolved from earlier systems such as meantone and Pythagorean tuning, which favored certain intervals at the expense of making some keys unusable. Tuning theorists and organ builders—including Werckmeister, Kirnberger and others—proposed various schemes that tempered fifths and thirds unequally to balance usable consonance with greater key flexibility. Johann Sebastian Bach’s The Well-Tempered Clavier (1722, 1742) is closely associated with the concept, though scholars debate whether Bach meant an equal temperament or a specific unequal well temperament.

In modern historically informed performance practice, well temperaments are used to recreate period sonorities and to explore key-specific colors lost under equal temperament. Today the term denotes both specific historical temperaments and the general approach of tempering intervals unequally to enable all-key modulation while preserving tonal variety.