The Liber quindecim missarum (Petreius, 1539), the Missae tredecim quatuor vocum (Formschneider, 1539) and the Opus decem missarum quatuor vocum (Rhau, 1541) appeared within a short period in two of the most prominent Lutheran centres. Each of the three printers evidently tried to build up a kind of ‘repertory’ of about a dozen masses by Franco-Flemish composers of Josquin’s generation and those immediately before and after, with a smattering of local glories and a couple of odd names. Striking is the almost total lack of overlap between the three collections, apart from two Josquin masses (L’homme armé super voces musicales and Fortuna desperata) in Petreius and Formschneider. But even this is due more to chance and the international fame of Josquin: the faulty copy Formschneider had at his disposal shows that the printers ostensibly sourced the two masses independently.
More distinctive and unusual is the repertory collected by Rhau, conspicuous for the absence of Josquin’s music and for its rather unusual character, perhaps motivated more by didactic considerations than by purely aesthetic ones. In some cases, such as the Missa Baisez moy by Petrus Roselli, Rhau apparently resorted to sources such as Antico’s Liber quindecim missarum, although the so-called ‘Torgau Choirbooks’, compiled under the supervision of Johann Walter for the new Lutheran chapel in Torgau Castle between the late 1530s and the early 1540s, which also transmit Roselli’s mass, might have been more readily available to him. In this chapter, I shall try to determine more precisely Rhau’s sources for his ten masses, thus reconstructing the filiation of this remarkable collection of masses.