The manuscript choirbook Studienseminar Albertinum B 111 in the Staatsarchiv München (D-Msa), dating from c. 1571 to 1578, contains three troped Magnificat settings. Troping the Magnificat has a long tradition in protestant Germany starting shortly after the Reformation and continuing up to Bach. The manuscript Albertinum B 111, however, was used at a Jesuit institution. This chapter investigates the transgression of confessional boundaries in the musical life of late aixteenth-century Germany.