chorale
A hymn tune harmonised in four parts, especially associated with the Lutheran tradition.
In Depth
A chorale is a hymn melody — typically simple, singable, and in regular phrases — harmonised for four voices (soprano, alto, tenor, bass). Martin Luther introduced congregational hymn singing during the Protestant Reformation, and these chorales became the foundation of German sacred music for centuries.
Bach harmonised hundreds of chorales, and his settings are the gold standard for the study of voice leading, harmony, and part-writing. Every music theory student studies Bach chorales because they demonstrate, in compact form, virtually every principle of tonal harmony. The chorale also served as the basis for larger works — Bach's cantatas and Passions frequently incorporate chorale melodies.
Bach's 371 chorale harmonisations have been used to teach harmony for over 250 years — they are studied by every music student in the Western world, making Bach history's most influential music teacher.