The 21-note subject of The Musical Offering, (Musikalisches Opfer), BWV 1079, was given to J. S. Bach by King Frederick II of Prussia when Bach visited his son, Carl Philipp Emanuel Bach, who was employed at the King’s residence in Potsdam. Instantly, Bach improvised a three-part fugue in front of the King and the audience. Later Bach returned to Leipzig and completed a set of pieces that we now know as The Musical Offering, based on Frederick’s theme.
The climax of Bach’s composition is a trio sonata in four movements, written for flute, violin, and basso continuo in the form of church sonatas: slow-fast-slow-fast. King Frederick II was a passionate amateur flutist, for whom Bach intentionally included the flute in the trio sonata, and to whom he dedicated The Musical Offering.
The Coffee Cantata, one of Bach’s few secular compositions, is a short, satirical dialogue between a father and his daughter. He forbids her to drink coffee; she demands three cups a day. He threatens; she doesn’t care. He cannot find her a husband if she continues to drink coffee. She already has suitors in the wings and secretly tells them that the marriage contract must allow her to drink coffee. At the end, everyone agrees, “drinking coffee is natural.”