It’s not for nothing that the young Bach walked 250 miles to Lübeck to hear Buxtehude perform. Johann Sebastian knew a good thing when he heard it and so, clearly, does Ton Koopman, whose scholarly edition of Buxtehude’s oeuvre is making available to us a substantial hoard of buried treasure from the early German Baroque. This is volume 17 of Koopman’s complete survey and, like its predecessors, it reveals the breadth and variety of the composer’s output.

The double CD contains chorale settings, sacred arias and cantatas but if that sounds stock in trade you’d be surprised at the musical novelties herein. Buxtehude wrote for church but also for familial occasions, his famous evening concerts and town celebratory events.

The performances are thoroughly idiomatic, Koopman encouraging a natural approach and embracing a quasi-improvisatory feel where appropriate. Original keys are restored (generally higher than the norm) and if these pose challenges to soloists, they are by and large met with aplomb. His sopranos blend perfectly despite some fearsome agility tests – listen to Gerlinde Sämann and Amarylis Dieltiens in the rapturous Laudate, pueri Dominum. Countertenor Maarten Engeltjes is ravishing in the poignant Klag-Lied, written to commemorate the death of Buxtehude’s father. My favourite is the joyous Schwinget euch himmelan (Lift yourselves heavenwards), written to celebrate some mercantile triumph with its jaunty invocation to “Bless all our commerce with success availing, May all our wheeling and dealing be blest” – wheeling and dealing in German being “Handel und Wandel”. Challenge’s engineering is detailed allowing every voice and instrument to come through with clarity.