This cantata was composed for the feast of St. John the Baptist, which fell on June 24, 1723, just a few months after Bach’s inauguration as Thomaskantor in Leipzig, and we don’t have records of any subsequent performances of it during his lifetime. The libretto is anonymous, except for the closing chorale which is a stanza of a hymn by Johann Gramann from 1548.
Maybe because the feast is on a fixed date and didn’t fall on a Sunday that year, Bach kept the orchestration relatively light. In addition to strings and continuo, only an oboe da caccia is needed, plus a clarino (trumpet) to reinforce the chorale line in the closing movement. Granted, the oboe da caccia was probably a bit of a curiosity in Leipzig at the time! From a vocal perspective, the piece calls for four soloists, and a choir that is only required for the closing chorale.
The first movement is an aria for tenor, set on a text that praises God for giving us the “horn of salvation” – a reference to Jesus in the Prophecy of Zechariah, which is mentioned in the Gospel of the day (Luke 1: 57-80). The voice is accompanied by strings and continuo, with occasional passages for solo first violin (when the rest of the violins come back in, the score is marked “tutti ma piano”). The meter is 12/8 and the flowing line only changes to runs of 16th notes to word-paint “preiset” (“praise”). Notable also is the change in the strings texture and the progressively raising intervals on “Das Horn des Heils, den Weg zum Leben” (“the horn of salvation, the way to life”).
Next is an alto secco recitative, which turns into a sweet arioso (marked “adagio”) as the text describes the “grace and love” with which Jesus will lead repenting sinners to the kingdom of heaven.
In the next movement, the novel oboe da caccia makes its appearance accompanying the soprano and alto, in what is formally a quartet with continuo, on a text that discusses the fulfillment of the promise made by God in Paradise. Structurally, the movement is da-capo, with an opening section in 3/4 that sees the voices moving mostly homophonically while the oboe decorates with 16th-notes passages. The middle section changes tempo and introduces some canonical elements between the voices. Due to the tessitura of the oboe, the sound of this ensemble is quite compact and full.
The fourth movement is a recitative for the bass, on text that continues to elaborate on Zechariah’s prophecy. The recitative switches to arioso on the last line as it prompts the congregation to “sing a song of praise to Him” – and as it does, it anticipates the melody of the chorale to follow.
The closing movement is a chorale on the fifth verse of “Nun lob, mein Seel, den Herren” by Johann Gramann. Instead of setting it as a regular chorale harmonization, Bach makes it the high point of the cantata by involving the full forces, adding a clarino (trumpet) to double the sopranos as they deliver the tune, and giving the strings their own independent thematic material to accompany the vocal lines, including a moto-perpetuo-style line for the first violin and oboe in unison.
