Originally Posted by Zack

To be fair, the term "experimental," in musicological and formally musically-educated generally has more of a Cagean flair to it, is in, the result is not determined, in some respect, whether composition or performance, so that the piece has an unknown result, thus, is an "experiment."

In more informal, general public circles, the term "experimental" seems to just mean, "sounds weird to me."

But, as far as I know, Stockhousen was not much of an experimentalist. He had ideas, and he set them forth in a structured, succinct manner. He may be old stuff now, but I think he could generally be considered equally as Avant Garde (for his time) or 20th century composition.

Originally Posted by Zack

Here's the thing about "Avant Garde." It literally means, "Advance Guard," or in other words, people at the current, cutting edge of new, usually artistic innovation. I mean, if you want to get technical about it, Beethoven was about as Avant Garde as it gets, back in his day. Haydyn's Symphony No. 94 was Avant Garde several decades earlier. Wagner was Avant Garde. So were the Beatles.