Although less pleasing on its own, her voice pushes and pulls in beautiful ways against Crowe’s lighter sound in the third Couperin lesson.

Many would not have given it a second look, but Rousset immediately thought of an unresolved mystery of Couperin’s oeuvre, a lost Ariadne cantata.

The previous night, in the same hall, he had given a recital of variations on a theme by Scarlatti that reached from Couperin to Kurtag.