Manuscript 27086 contains music by Giorgio Flori, Jacobus Vaet, Philippus de Monte, and Orlandus Lassus, all composers with ties to, or whose music was known at, the Viennese court of Maximilian II. Manuscript 27089 was most likely produced at the court of Rudolf II in Prague. The codex consists primarily of polyphonic Mass settings by Philippus de Monte, the Kapellmeister Rudolf inherited from his father. For these masses, De Monte drew on material from motets and madrigals by composers including Cipriano de Rore, Alessandro Striggio and Philippe Verdelot. These ‘sources of inspiration’ were also included in the manuscript itself. Both choirbooks eventually made their way to Brussels in 1912, when the conservatory acquired them from an antiquarian bookseller in Leipzig.

The Alamire Foundation is now conducting further research into these sources. Once completed, the images will be made accessible alongside detailed metadata through the Integrated Database for Early Music.