The general listener is often wedded to the idea of originality as the hallmark of genius. Professional musicians, having had more of an opportunity to delve into the formation and evolution of a composer’s musical language, know better. Thankfully, more and more are willing to share the fruits of their researches in ways that expand our understanding – of works, as well as the world of the composer – in novel recording projects such as harpsichordist and organist Benjamin Alard’s.

By the time he reaches the end of his complete account of JS Bach’s keyboard works, Alard will have been the first musician to do it. On the strength of...