The Orgelbüchlein Project is a collective composition project aiming to complete Bach’s unfinished manuscript known as ‘Orgelbüchlein’. In the ‘Little Organ Book’, Bach laid out a complete hymnal of short organ chorale, 164 in all, but only completed 46 of them. Why the remaining 118 were left as blank pages, with only a title at the head, remains a mystery, but they inspired organists William Whitehead to found the Orgelbüchlein Project, in which contemporary composers are invited to contribute a piece to completing the collection. The resulting collection, to be published in eight volumes, represents a cross-section of the most interesting composers at work today across Europe.