The period of the Union between Saxony and Poland (1697 - 1763) is regarded as the most glittering phase of court music in Dresden. The first SLUB project on the collections of musical scores of this epoch, "Schrank II", was devoted to instrumental music and resulted in numerous musical discoveries and insights into the history of music.

It is now planned to crown the treatment of the precious music legacy bequeathed by the double monarchy by processing the mostly vocal arrangement collections of musical scores from the Dresden Catholic Court Church and from the basis of the Royal Private Music Collection, which is composed of the estates of musical scores left by prominent members of the House of Wettin.

As a result, a freely accessible digital source service beckons in a new dimensional quality. Included in the approx. 1,500 music sheets are a large number, which have hitherto remained hidden from research and practice. The task of this project is to develop the material culminating in the original movements to Bach's Missa in B minor in accordance with the state-of-the-art RISM source reference database, professionally scanning it as well as utilising it both in the SLUB Digital Collections and supraregional platforms.