Johann Sebastian Bach's chorale harmonisations, alternatively named four-part chorales, are Lutheran hymn settings that characteristically conform to the following:
- four-part harmony
- SATB vocal forces
- pre-existing hymn tune allotted to the soprano part
- text treatment:
- homophonic
- no repetitions (i.e., each syllable of the hymn text is sung one time)
Around 400 of such chorale settings by Bach, mostly composed in the first four decades of the 18th century, are extant: