This Stockhausen no longer tilts at windmills, he drives crash test vehicles into them.
I saw Stockhausen live at an International Trumpet Guild conference in Rotterdam in 1992. His son, Markus, is an excellent trumpeter; unfortunately he has focused most of his artistic efforts to his father's compositions, including the wacky aria from Stockhausen's Licht opera cycle. Markus was Jesus, a soprano soloist was Maria, the two accompanied by taped electronic spurts and geegaws. The elder Stockhausen spoke before the performance, making sure we all knew that the performers were not to look at each other while they played and moved about in dramatic fashion (including a recreation of the Piéta, quite remarkable to recline while playing the flugelhorn and not looking at the person you are reclining against).
I later gained a greater appreciation for what a marvelously crazy man Karlheinz was when reading his articles from the 50's and 60's for a history of music theory course, and studying some of his compositions in analysis courses. Tim does point out a big problem with many integral serial compositions: all they express is the process, rather than using the process to get at something new. Stockhausen at least tries to do this in later works, especially when using moment form as an attempt to portray eternity. Windmills, indeed.