@theothr1 said:

1. I am NOT trolling
2. I am NOT trying to stir the pot
3. I LOVE Phish...
4. ...and have since 1992

not that any of that means very much...i just want it to be clear that I am asking the following question out of sincere curiosity: how do we know that the 31st's Tweezer jam was NOT composed and rehearsed???...and, for god's sake, no, I don't mean note for note...I'm referring to each individual movement having been pre-outlined...for lack of a better example, kinda like Miles' s concept for Kind of Blue

I can understand why you would ask the question...this tweezer seemed like a composed masterpiece. So here are my thoughts and an "answer" to your curiosity question:

The triumphant ecstasy that erupts out of this song is clearly not rehearsed, and the perfect timing and magical execution are like lightning in a bottle. I think everyone will generally agree on that.

A recent similar example of unexpected eruption (although not quite as epic as this tweezer) might be Limb by Limb from St. Louis last year. I also think this was clearly not rehearsed, as both it and this tweezer took so long to develop the triumphant moments in the songs.

An example that I might suggest would better fit your "rehearsed" or "composed" description here would be Super Ball Mound. The joy that explodes at out of that little 2 minute solo at the end of the song has "more" of a feeling of rehearsal. There's no lead up or exploratory build up...it's certainly not composed note for note, but Trey had to have planned that to some degree because it's not a usual spot for a jam.

A final note--I think what can come into play is any member(s) vision for a song or jam prior to really getting into it. Like "hey, let's explore this song or that song tonight." Do I think that they scripted any part of the actual composition of this Tweezer? No. Do I think they sat around at set break and possibly discussed "hey, let's open with tweezer and ride the wave for a while..." -- certainly possible.

Phish explored different themes and managed to brilliantly execute IT. They've made a career out of trying to capture IT and share it with us. In Tahoe, they just simply NAILED IT.