What do you mean?
I mean mold-breaking songs. Earlier in the thread thenewgreen wrote this: When I was about 12 years old, I heard the Beatles song I am the Walrus for the first time. It was then that I realized that both music and lyrics could be far more than what I had previously considered.
There are many ways of "breaking the rules" -- weird music, as you say, does that.
Ah, I see.
The first one that comes to mind is "We Have Heaven", by Yes (Fragile album). In that song, Jon Anderson laid down many vocal tracks, and sang harmony (and a 'round' format), with himself - no other vocalist. Kinda blew my teen-aged mind a little. Also, in the same song, they did something really cool. The song ends abruptly with a slamming-door sound, followed by footsteps walking away. Later, on the other side of the album, after the last song, we hear the door open, and "We have Heaven" finishes. So very cool.