Bach’s harpsichord concertos have proven extremely popular, though several were originally written as concertos for another solo instrument - either violin or a woodwind instrument. But we know nothing about any such preliminary versions in the case of the A-major Concerto BWV 1055. Its enchantingly songlike middle movement inevitably makes one think of the oboe d’amore, though there is in fact no reason to suppose that its idiomatic, spirited harpsichord writing was conceived from the outset fo...