As with scarcely any other work of the 17th century, Monteverdi's Vespers has found its way into today's repertoire. Nevertheless, the Vespers still leaves open many questions. The new edition, with its critical examination of the sources, takes up these oft-discussed issues concerning scoring possibilities, performance practice, transpositions and liturgical unity. It is based on all of the surviving copies of the print of 1610 and the earliest handwritten entries have also been critically examined and evaluated. Performance material is organized in a flexible manner to allow for the use of different instruments in those movements without obbligato instruments in order to reinforce the vocal parts and thus invites an individual musical approach to the challenge presented by Monteverdi's Vespers.