This evening’s programme includes three triple concertos: the monumental Concerto in A minor for harpsichord, flute, violin and strings, which started life as two separate organ works, the Concerto in F for harpsichord, two recorders and strings, Bach’s fascinating transformation of the Fourth Brandenburg Concerto, and the spectacular but seldom heard Triple Violin Concerto in D – a reconstruction of a lost original work.

For the last 27 years of his life, Bach was employed to write liturgical music for the four principal churches in Leipzig. Yet somehow he found time to direct proceedings at the Collegium Musicum, the famous association that gave weekly concerts at Zimmermann’s coffee house. These concerts gave Bach the opportunity to write a large number of new concertos and reinvent many earlier masterpieces as entirely new works.