I would suggest everybody read Hal Crook's book/method on performing free jazz. It's nothing short of amazing.
There's a difference I like to distinguish between "free" jazz and "out" jazz. Free improvisation does not need to be "out" in order to be free, in other words, it's musical language does not have to be atonal, textural, arhythmic, etc in order for it to be completely improvised. It can be, but that's just one particular texture. I personally prefer to play and listen to free performance where "out" is used sparingly.
There's a difference I like to distinguish between "free" jazz and "out" jazz. Free improvisation does not need to be "out" in order to be free, in other words, it's musical language does not have to be atonal, textural, arhythmic, etc in order for it to be completely improvised. It can be, but that's just one particular texture. I personally prefer to play and listen to free performance where "out" is used sparingly.