I think you're looking for the late show, 2/11/70, Bill; the Dead + Arther Lee, Peter Green, Duane, Gregg, Berry, and maybe Danny Kerwin.
 
Peter

This is an interesting thread!
 
So right now I'm listening to Bill's choice ...
Live Dead: Dark Star > St. Stephen > The Eleven

It's one of the few pieces that gets an improvement from vinyl to CD.  On the LP, Dark Star was on Side One, then you had to flip over the album for St. Stephen & The Eleven.  On CD it's all one continuous piece.
 
Bill, tgo

Many years ago a friend played me a reel-to-reel of a broadcast of that show. During the drummy section of Lovelight, they gave a station ID; at the end of the show there was a long pause (dead air after Dead air, if you will), then the DJ said I'm sorry - that was a really stupid place for that ID - but other than that, wasn't that just the most amazing thing you've ever heard?!?!?  And I just sat there in awe.  
Yes, after many, many times of flipping the disk as fast as I could, I was very excited to get the CD & hear it straight through again - but I changed to the next disk quickly, too, because I always thought TOYLL was part of the same jam.  Sounded like it on the tape, but with the CD, I'm not so sure.  Maybe I better go listen again, huh?
 
Peter

Live Dead: Dark Star > St. Stephen > The Eleven (+1)
 
Also:
 
Hendrix Band of Gypsies Machine Gun
 
Makes the hairs on the back of my neck stand up when he holds those long, screaming bends about 1/3 of the way through...vicious tone.

Sorry, Bill, somehow I missed your response until now. According to a bio of Townes Van Zandt I read (I'd cite it, but don't recall which one it was) Duane was hanging at Armadillo World Headquarters for a TVZ gig; afterwards, while they, the owner, and some others were upstairs committing felonies, some one stole the entire stock of beer.  Duane told the owner not to publicize it, but let a few of the proper people know that they'd be there the next night; about 1/2 of ABB played for free to restock the cooler, and among what they played was the 1st MJ.
 
Peter

I've seen a couple recent Stanley Clarke jams featuring Stu Copeland on youtube.    
 
Maybe the two of them will invite Steve Vai sometime???

For whatever it might be worth, with Al Di Meola, Steve Vai, Steve Morse, and Joe Satriani.

That was worth a good bit to me.

Chicago transit athourty..... Poem  

CTA - yes!
 
Also - Liberation off the first album.

Gov't Mule - Cortez the Killer from Live With A Little Help From Our Friends.
 
Not the smoothest ending but certainly 14:00* of connected geniuses!
 
Warren Haynes, Allen Woody, Matt Abts, Marc Ford, and the incomparable Bernie Worrell.
 

 
 
*actually the whole 4 hours show from 12/31/1998 is a musical monsterpiece.

Paul; that was wonderful, thanks!

Everyone keeps saying Dark Star, do you mean this:
 

 
?