J. S. Bach leads the first performance of Gelobet seist du, Jesu Christ, BWV 91, in Leipzig, based on Luther's 1524 Christmas hymn.

Johann Sebastian Bach was a German composer and musician of the late Baroque period. He is known for his prolific output across a variety of instruments and forms, including the orchestral Brandenburg Concertos; solo instrumental works such as the cello suites and sonatas and partitas for solo violin; keyboard works such as the Goldberg Variations and The Well-Tempered Clavier; organ works such as the Schübler Chorales and the Toccata and Fugue in D minor; and choral works such as the St Matthew Passion and the Mass in B minor. Since the 19th-century Bach Revival, he has been widely regarded as one of the greatest composers in the history of Western music.

Gelobet seist du, Jesu Christ, BWV 91, is a church cantata by Johann Sebastian Bach. He wrote the Christmas cantata in Leipzig in 1724 for Christmas Day and first performed it on 25 December. It is based on the hymn "Gelobet seist du, Jesu Christ" by Martin Luther which was 200 years old when Bach wrote the work.