i went to a whole load of those Stockhausen shows at the barbican the other year, and saw hymnen, it's a beautiful sweetly utopian piece of music, utterly caught up in possibilities and ideas and the inventiveness of recorded sound.
Me and my mates had quite bad seats, so we complained, as there was a whole row near where Stockhausen was controlling that was empty, we had a word with the usher guy, who had a word directly with Stockhausen as we were desperate to get some good seats, it was incredible hearing that sound woosh around the theatre, and Stockhausen let us sit in his special seats. All the time as we moved into those seats Stockhausen was watching us patiently with paternal eyes ( i thought ) . We literally had the best seats in the house then, and it was amazing.