A nifty way in which Bach modulates, particularly from a minor to a major mode, is by simply pivoting around the tonic of the previous minor key.
In the final movement “Badinerie”, of his Orchestral Suite No. 3, for instance, he will often give the tonic chord a cape, turning it into a super-tonic chord in the following phrase.
For example, the movement opens in B-minor and is asserted by a nice, strong iiø – V7 – I progression.
However, quickly attaching a cape to B-minor in bar 4, Bach turns the B-minor chord into an ii of VII.
Or, in other words, a supertonic of A-major (what was the leading tone, the VII, of B-minor before).
This article is a supplemental short to a much longer analysis of Bach’s “Badinerie”.