Long attributed to the Eisenach composer Johann Christoph Bach (1642-1703), this work was later re-ascribed to Johann Sebastian Bach, though from an earlier period in his career than his other motets. This is Bach’s earliest known motet, written not later than 1712, and it may be his most unusual (leading scholars to be suspicious about it truly being from the hand of J.S. Bach). The doubling choirs are used most often antiphonally, with Chorus II echoing Chorus I almost exclusively throughout the first 65 measures or so; at that point, the choral entrances come closer together, overlapping continuously until they reach rhythmic and textual unity in m. 77. Shortly thereafter (m. 84), the music changes dramatically:
|Part I||Part II|
|Texture||Homophonic and antiphonal||Polyphonic|
|Independent voice parts||8||4|
|Length||83 measures (1-83)||32 measures (84-116)|
“Rondo”? “Chorale fantasia”? I’m sure you’re wondering what this is all about; after all, isn’t this a motet? Why in the world would I say “genre” for parts I and II. It’s quite simple actually. The first part is remarkably like a rondo, a genre we normally associate with the Classical era, rather than the works of Bach, although its predecessor, the rondeau, would have been known to Bach, who studied the French harpsichord music of François Couperin (1668-1733), his contemporary.
The resulting effect of a rondo is that there is indeed a refrain – at the very least a textual refrain, but given that the rhythm is unaltered, this little phrase feels like a musical refrain as well. Did Bach intentionally try to create a rondo? Well, no, probably not, if by that question we mean was he attempting to follow a particular form. But by constantly repeating this rhythm and these words, Bach makes all the stronger the point of the text: I will not let you go, Lord, until I am blest. No matter how long, how strongly , how tenaciously I must do so, I will not let go until…when? When I am blest.
Referring back to the opening above, you can see that Bach here puts three flats in the key signature, but looking at the cadence, you can see this is clearly in f minor. This is an example of a partial signature,which was fairly common in Bach’s day for works in the minor mode. But what I find so unusual is how strongly tonal and chordal this work is. It strikes me as so un-Bach, which may be one reason why scholar long attributed the work to another Bach, and to this day still count this motet as “spurious” or “apocryphal”.
Now, about the chorale fantasia. this is more obvious. At m. 84 the entire character of the work changes to what we would consider “more typical Bach”. The lower three voices weave a more complicated imitative fabric, above which the sopranos sing a chorale tune in long notes. This is something we’ve seen before in Bach, including in Cantata 140, Wachet auf, among others.