I would advise people who think free jazz is aimless horn honking made by self important charlatans (which it is at its worst!) to check out some of the groups who straddle the border between the free and straight worlds (by straight I mean music that retains elements of traditional jazz such as heads, songs, solos, occasional standards etc. rather than any sense of "seriousness"). The ICP Orchestra, Art Ensemble of Chicago, Vandermark 5, NRG Ensemble etc. are good places to start. If you can get into that then you might want to come back to the freely improvised stuff later (which I know isn't what this thread was intended to be about, but I think that is what a lot of people take free jazz to mean).
Best (perhaps) concert I've ever been to:http://www.youtube.com/watch?v=SeNtD...eature=related
That's my head obnoxiously swinging back and forth in front of Han's snare drum!