There is no doubt about the authenticity of the eight-part Singet dem Herrn ein neues Lied
. It dates perhaps from the New Year 1727, and is a setting of words from Psalm 149, verses 1–3 and Psalm 150, verses 2 and 6, separated by a chorale movement based on verse 3 of the chorale ‘Nun lob, mein Seel’ in Choir 2, which is answered in Choir 1 by a free setting of a chorale text related to ‘O Ewigkeit, du Donnerwort’. The three-movement structure of the work suggests that Bach thought of it as a sort of choral concerto, and this is borne out by the mighty first movement, which is laid out in the ritornello plan: statements of the theme in each of the main keys visited are separated by modulating episodes. This was this piece that Mozart heard during his famous visit to St Thomas’s Leipzig in 1789, as reported by Friedrich Rochlitz:
Hardly had the choir sung a few measures when Mozart sat up, startled; a few measures more and he called out: ‘What is this?’ And now his whole soul seemed to be in his ears. When the singing was finished he cried out, full of joy: ‘Now, there is something one can learn from!’
And learn from it Mozart certainly did, as his Requiem shows.
from notes by Peter Holman © 1990