The ZKM ; Institute for Music and Acoustics (IMA) is presenting a DVD publication documenting the production process and premiere of Karlheinz Stockhausen’s composition “Strahlen”. “Strahlen” is a version for percussion and ten-channel audio recording of “Hochzeiten” from “Sunday” from the “Light” opera cycle. As a commissioned piece by the ZKM ; Center for Art and Media, the piece was performed for the first time in 2009 by László Hudacsek (vibraphone) and Kathinka Pasveer (sound direction) The collaboration between the ZKM and Karlheinz Stockhausen began back in 2003. Initially, Stockhausen’s ideas were thoroughly analysed in order to develop technical procedures to produce the composition. From the music score and extensive fax correspondence, it became clear that Stockhausen had precise sound concepts for all details. In order to satisfy these ideas, the entire sound spectrum of a vibraphone, among other things, had to be sampled at various volumes with a certain number of drumsticks. This created a sample library of 2000 vibraphone sounds. The documentary film provides an interesting insight into the incredible complexity of the production process. Special techniques had to be used to record Stockhausen’s tenchannel composition with its spatial information on a DVD. A number of spatial sound formats were experimented with: The acoustic properties of the performance space are incorporated into a binaural recording with artificial head; by using an HRTF (Head-Related Transfer Function) version, the impression of a “surround environment” is produced within an ideal space when listening with headphones; a third version, on which the ten voices are mixed together into five channels, provides a differentiated listening experience with a 5.1 sound system. In addition, the DVD contains an exclusive interview, which Ludger Brümmer, head of the IMA, held with Karlheinz Stockhausen.