At the heart of the program is the development of the double choir - a special compositional style in which two choirs sing alternately or in unison, creating a powerful, multi-layered sound. The chamber choir Forum Vocale Rhein-Sieg e.V. brings this tradition to life with impressive examples from three centuries.

It begins with Heinrich Schütz, who introduced the magnificent Venetian multi-choral sound to German music with his "Psalms of David" during the Thirty Years' War. Around a century later, Johann Sebastian Bach continued the art of the double choir. Finally, in the late 19th century, Johannes Brahms took up the motet form again.

Choirmaster Georg Bours has put together a finely tuned program for this project that juxtaposes the different styles and soundscapes of the three eras and at the same time relates them to one another.