I've had this REALLY OLD version of Ants Marching on my computer. I'm 99% sure it came from the old H.O.R.D.E. tour.
When I downloaded the song, the title says "Dave Matthews Band/Phish...Ants Marching". Another download is labeled "Dave Matthews Band and Trey (Phish)".
Anyways, at 5:01 of the song, Dave says something on the mic to the extent of "Now lets go Timmy"...and instead of Boyd's usual violin solo, a lead guitar comes in. The sound of the guitar REALLY sounds like Trey's Langudoc, but I'm convinced Dave introduced (as he often does) Tim and his solo.
Any takers on this one? Who was it playing that solo?