On this week's Learning to Listen, you'll hear a refresher on what a "cantata" is, and you'll hear Johann Sebastian Bach's Schwingt freudig euch empor ("Soar joyfully aloft," in English).
Bach was the king of the cantata, and wrote more than 200 of them. Although most of the music in them is original, he found occasions to recycle bits.
Such is the case with Soar joyfully aloft, which originated as an "homage cantata" paying tribute to a professor at the University of Leipzig in 1725.
Bach had already used some of it for a "congratulatory cantata" in 1726 before he altered it for Advent in 1731. It should come as no surprise that he used it once more, again as a congratulatory cantata, for the Rivinius family of Leipzig in 1735.
All of that can be overwhelming, and each time Bach used the music, he changed bits and pieces. In the case of the Advent Cantata of 1731, he added four sections based on Advent-related hymns from Martin Luther and Philipp Nicolai.