welltemperament

Well temperament is a term used in music theory to describe a family of tuning systems for keyboard instruments in the 17th and 18th centuries. In well temperament, the octave is divided into 12 pitches that are not all the same size, as in equal temperament, but with a deliberate compromise that makes all major and minor keys usable while giving each key its own characteristic color. The goal was to enable modulations to distant keys without producing instruments that sounded sour or unusable.

Historically, well temperament encompasses several distinct tunings, including Werckmeister, Vallotti, and Kirnberger temperaments. These systems typically alter fifths and thirds to distribute out-of-tune intervals more evenly across the keys, preserving more consonant triads in many keys while allowing other keys to sound more tempered or colored. This approach contrasts with mean-tone temperaments, which prioritize pure thirds at the expense of key usability, and with equal temperament, which keeps all keys equally tempered but reduces key-specific color.

The emergence of well temperament supported more flexible harmonic exploration in Baroque and early Classical music. Composers such as Johann Sebastian Bach demonstrated a repertoire that could be played in a wide range of keys, exemplified by The Well-Tempered Clavier, a work intended to showcase the practical viability of these tunings. The exact tuning of a well-tempered instrument varied by locale, instrument, and maker, rather than by a single standard.

Today, well temperament is studied as part of historical performance practice and is occasionally revived for period instruments. It is valued for its tonal variety and its historical role in expanding the expressive possibilities of keyboard music.