J. S. Bach Harpsichord concerti
How many harpsichord concertos did Bach write? How many survive? What constitutes a ‘Bach harpsichord concerto’?
These are not simple questions.
An easy answer might be: ‘Six, or seven if you include the triple concerto with flute and violin, or eight if you include the re-working of Brandenburg 4’. Certainly it is eight that Christophe Rousset recorded with AAM/Hogwood for Decca and the same eight that Richard Egarr will be recording with AAM/Manze for Harmonia Mundi USA. [And for those into BWV numbers, the six are BWV 1052, 1053, 1054, 1055 1056 & 1058; the seventh is 1044; and the eighth is 1057.]
But read on...
The concerto in the modern sense of a work for solo instrument and larger ensemble came into being in Italy around 1700, Vivaldi becoming a great exponent of this form and the violin often being the solo instrument (or the primus inter pares if more than one solo instrument was featured). The concerto for solo keyboard instrument was at first unknown, and J. S. Bach was one of the first to write for this combination. But even Bach’s harpsichord concertos didn’t start life as such, and as with most of his surviving work for instrumental ensembles, they are products of his common practice of transcription and re-composition which he undertook during his Leipzig years (1723–1750). When, in 1729, he became director of the Leipzig Collegium Musicum, he needed to provide works for performance in, among other venues, Zimmermann’s coffee house, and it is thought that he reworked many earlier concertos for this purpose. Some of the earlier versions survive (e.g. BWV 1058 and 1054 are based on the violin concertos BWV 1041 (A minor) and BWV 1042 (E major), and provide interesting ideas about how to ornament the violin concerto) while others are lost (e.g. 1053 and 1055, which may have been oboe concertos).
So while the answers are not clear, at least the questions are!