'''Mass in B minor''' ('''BWV 232''') by Johann Sebastian Bach is a musical setting of the complete Ordinary of the Latin Mass. The work was one of Bach's last compositions, not completed until 1749, the year before his death. Much of the Mass gave new form to vocal music that Bach had composed throughout his career, dating back (in the case of the "Crucifixus") to 1714, but extensively revised. To complete the work, in the late 1740s Bach composed new sections of the ''Credo'' such as "Et incarnatus est".
It was unusual for composers working in the Lutheran tradition to compose a Missa tota and Bach's motivations remain a matter of scholarly debate. The Mass was never performed in its entirety during Bach's lifetime; the first documented complete performance took place in 1859. Since the nineteenth century it has been widely hailed as one of the greatest compositions in musical history, and today it is frequently performed and recorded. Carl Philipp Emanuel Bach archived this work as the ''Great Catholic Mass''.
- Category: 1749 compositions
- Category: Compositions by Johann Sebastian Bach
- Category: Compositions in B minor
- Category: Masses (music)
- Category: United States National Recording Registry recordings
- artist-composer: 24f1766e-9635-4d58-a4d4-9413f9f98a4c
- composer: Johann Sebastian Bach
- recording-performance: 235f2674-f941-4ed1-90b5-2eb41d990992