An opportunity arose for Bach when in 1729 the Collegium Musicum of Leipzig found itself in need of a new director. This organization, which was one of the earliest ensembles to produce and perform public concerts in the modern sense, had been founded in 1701 by Bach’s friend (and godfather to his second son) Georg Philipp Telemann.
Led by Bach the Collegium Musicum performed a weekly two-hour concert at the largest and most prestigious coffee-house in Leipzig, owned and operated by Gottfried Zimmermann
Bach held the directorship of this Collegium through 1737, and again from 1739 through 1741.
For these concerts he had to compose or obtain, and rehearse and perform, a vast quantity of music. His 10-year tenure as director of the Collegium meant producing an estimated 500 concerts. A major orchestral genre of the time was the overture with appended suite of dances (Telemann is reckoned to have composed many hundreds). There are four which survive from Bach’s hand. Three of them, the one in C major, and both of those in D major, were probably composed in the 1710’s and revived for the Collegium concerts. The overture in B minor for flute and strings is more likely to have been composed anew for the Collegium and the only surviving parts date from the late 1730’s. As in other examples of this genre, the opening movement is the largest in scale, alternating between a slower section of majestic character and a quicker, fugal section. It is then followed by a series of dance-movements: a Gavotte (even though it is labeled “Rondeau”), a Sarabande, a pair of Bourrées, a Polonaise with a variation, and a Menuet. To round it off a movement that superficially resembles a fast Gavotte, but which Bach calls “Badinerie.”
