At least when talking about prog rock it seems like most people call songs "filler" when they're experimental and/or very different.

So in that case I'd say that "filler is experimental songs/segments that the band really digs and decided to include on the album, even though they realize it's different and might not appeal to most listeners". I like that kind of "filler" though, since they show more of the song-writer's personal preferences. :)

who knows?

maybe all of our favorite songs are filler, and all the ones we hate are supposed to be the focus.

but probably not.

The last part of the Moonchild track off King Crimson's debut ..

Nah, if I remember correctly even the band themselves disowned that one. It's filler because it's so bland and just takes up space without contributing to the album.

Well, my defintion of filler is "random audio collages thrown into an album to break songs up." but hell, what do I know?

i argue that cuckoo cuckoo from SJ is filler. It kills the flow of the album and isn't a good song, either. but you're right about the rest of their albums, especially all the ones that came before Feels. My goodnes where those tough to listen to, and even feels is full of filler.

My definition of filler is the songs you find yourself skipping after you've heard the album 3 or 4 times.

Filler is $$$$...anything that was put togther to "fill" an album.....Because there was so much on there contract it makes the talent disappear. It's sad because so many good bands go bad because of Record labels

That's a pretty good way of looking at it.

Filler within a track? That could cause a time warp.