Johann Sebastian Bach composed the church cantata Herr Christ, der einge Gottessohn (Lord Christ, the only Son of God),^[1] BWV 96, in Leipzig for the 18th Sunday after Trinity and first performed it on 8 October 1724. The chorale cantata, part of Bach's second annual cycle, is based on the hymn in five stanzas "Herr Christ, der einig Gotts Sohn" by Elisabeth Cruciger, published in Eyn geystlich Gesangk Buchleyn in 1524.

The hymn, related to mysticism and comparing Jesus to the Morning star, matches two aspects of the prescribed gospel for the Sunday, the Great Commandment and a theological dispute about the term "Son of David". An unknown poet kept the first and last stanza for the first and last movement of the cantata, and paraphrased the inner stanzas as four movements, alternating recitative and aria. Bach set the first stanza as a chorale fantasia with the cantus firmus in the alto, adding sparkle by a "dancing" soprano and the illumination of a sopranino, which he used for the first time in his cantatas. In the four inner movements, all four vocal parts have their solo. A tenor aria is accompanied by an obbligato transverse flute, a part written for a virtuoso player. A bass aria is accompanied by an oboe and strings, acting as in a Venetian concerto. The cantata is closed with a simple four-part setting of the hymn tune. Bach performed the cantata again in later years, with minor changes to the scoring.

Bach wrote the cantata in 1724 for the 18th Sunday after Trinity as part of his second annual cycle of mostly chorale cantatas. The prescribed readings for the Sunday were from the First Epistle to the Corinthians, Paul's thanks for grace of God in Ephesus (1 Corinthians 1:4–8), and from the Gospel of Matthew, the Great Commandment (Matthew 22:34–46), also mentioning that the byname "Son of David" was discussed in a "theological dispute" of Jesus and the pharisees.^[2][3]

The cantata text of an unknown author is based exclusively on the hymn "Herr Christ, der einig Gotts Sohn" in five stanzas by Elisabeth Cruciger (1524).^[4][2][5] The hymn is based on a Latin Christmas hymn, "Corde natus ex parentis", by Aurelius Prudentius. It is the first hymn by a Lutheran reformer which continues late medieval mysticism.^[5] Martin Luther appreciated the hymn so much that he placed it at the beginning of an early hymnal,^[2] Eyn geystlich Gesangk Buchleyn.^[5] The chorale was originally associated with Epiphany, but also with the 18th Sunday after Trinity.^[6]

The hymn's first and last stanza in their original wording became the outer movements, as usual in Bach's chorale cantatas.^[3] The unknown librettist paraphrased stanzas 2 and 3 to the cantata's respective movements, and stanza 4 to movements 4 and 5. The Gospel asks how Jesus, of David's descent as said in 2 Samuel 7, can also be David's Lord, as claimed in Psalms 110:1. The hymn tries to answer this question, comparing Jesus to the Morning star, an image also used in the hymn "Wie schön leuchtet der Morgenstern", the base for Bach's cantata Wie schön leuchtet der Morgenstern, BWV 1.^[6]

Bach performed the cantata at least three times, first on 8 October 1724, a second time probably on 24 October 1734 when the sopranino was replaced by a violino piccolo,^[3] and a third time probably on 1 October 1740. The Bach scholar Christoph Wolff suggested performances in 1744/47,^[7] Klaus Hofmann in 1747, when the corno part was given to a trombone.^[3]

The entries are taken from the listing on Bach Cantatas Website.^[12] Instrumental groups playing period instruments in historically informed performances are marked green under the header Instr..