The music on this evening’s programme, originally for keyboard, offers a snapshot of JS Bach’s domestic music making. Wilhelm Friedemann was Bach’s eldest son and a gifted keyboardist and composer, but died in poverty after a chequered career. He was about ten when Bach began to compile this book in 1720. It begins with an explanation on clefs and how to finger, and its contents include early versions of the preludes from the Well-Tempered Clavier. The two books Bach compiled for his second wife, soprano Anna Magdalena, date from 1722 – the year after their marriage, when she was 20 – and 1725. The first book’s works are all his, but the second features other composers including Hasse and Couperin, plus Christian Petzold’s famous Minuet in G. It’s also not impossible that Anna Magdalena herself authored some of the unattributed pieces.