Johann Sebastian Bach (1685-1750) was a big fan of Martin Luther, who composed many of the chorales that we still hear in church today. One of Bach’s most famous pieces that was inspired by Luther was “Nun komm, der Heiden Heiland,” specifically the chorus of this piece.
This movement sounds older than it is. Bach doesn’t seem to follow the modern styles in this piece. This movement has a lot going on, but it all works together well contrapuntally. At the beginning of the movement, which is in a minor key like Luther’s chorale, the oboes are moving in sixteenth notes and the strings in eighth notes, but as the opening moves on, the strings and continuo begin to play sixteenth notes in imitative counterpoint of each other and the oboes. This style is an older style which wasn’t commonly used when Bach was writing.
When the singers come in, they also participate in the imitative lines, both with each other and with the instruments. For example, the tenor line in measure 20 sings the same rhythmic motive of an eighth followed by two sixteenth notes as is in the oboe part continuously. The original chorale melody doesn’t come into the piece until measure 22 and then, according to the Burkholder, it comes in as a cantus firmus, which is an ancient device at this point. The text works with this feeling of ancientness because it was written by Luther nearly two-hundred years before. Specific examples of effective text painting include the text painting on the phrase “Nun komm, der Heiden Heiland” because the rhythm is much slower, and therefore much more insistent and pleading in contrast with the moving notes around it.
Another example of cool text painting is at all parts singing the word “Welt” which means “marveled.” Before this word, all of the parts had been singing mostly eighth notes, but on this note they begin to sing only in sixteenth runs. These runs evoke a sense that the singer is in awe. This piece is like a concerto grosso in that in the beginning, the strings and oboe, in their style and the way it is contrapuntally arranged, sound like a small ensemble and when the voices and the string and wind ensemble join together it sounds like a large ensemble. It is also similar to concerto grosso in that it is written, as the Burkholder says, with the chorale phrases framed by instrumental ritornellos, which also happens in concerto grosso. At measure 43 through the end of that phrase, the vocal material begins to imitate the instrumental part exactly. Then, when the vocal part comes in again at measure 45, it begins to repeat the same ideas as the vocal part at the beginning of the movement.