On the 15th of June 2011 I had the great privilege of interviewing Rolf Gehlhaar - composer (and Stockhausen's assistant from 1967-1970). Rolf gave me so much information and made such a great contribution to my research on the performance practices surrounding electronic instruments in Stockhausen's Mikrophonie I that I will be processing it for months!Here's a screenshot from a short video I took in which Rolf demonstrates some of the filter and fader techniques used in Mikrophonie I on a mock-up of the original machines that I built as part of my PhD research.
Thanks Rolf!
http://gehlhaar.org/
