Georg Hajdu’s composition “gemischt und durcheinander” (mixed and jumbled) for 35-part choir and organ, based on a text by Hermann von Helmholtz, explores the nature of sound and noise. The score, the result of a fruitful collaboration with the organist and cantor Anne Michael, is transmitted in real time from a central server to iPads and executed by the choir and the organ. The technologies developed by the ligeti zentrum were used for this purpose.