Keyboard concertos by Johann Sebastian Bach left Weimar in 1717. Many of Bach's orchestral harpsichord concertos are adapted from a model with one or more violin solo parts. Several of these earlier models are extant. The oldest of these is Vivaldi's concerto for four violins, RV 580, published in 1711, model for Bach's concerto for four harpsichords, BWV 1065. Bach replaced the part of his fourth "Brandenburg Concerto", BWV 1049, composed in 1721 or earlier, by a harpsichord part when he reworked it to the harpsichord concerto BWV 1057. Bach's extant violin concertos BWV 1041–1043, two for a single violin soloist and one for two violin
Keyboard concertos by Johann Sebastian Bach timing matched the publication of the first ever collection of keyboard concertos, the widely acclaimed and well-selling Organ concertos, Op.4 of George Frederic Handel published in London and Paris in 1738. The harpsichord concertos were composed in a manner completely idiomatic to the keyboard (this was equally true for those written for two or more harpsichords). They were almost certainly originally conceived for a small chamber group, with one instrument per desk, even if performed on one of the newly developed fortepianos, which only gradually acquired the potential for producing a louder dynamic. The keyboard writing also conforms to a