The Grateful Dead and the Allman Brothers Band famously shared the stage at Watkins Glen in 1973 but, ever since, onstage collaborations by founding members of the seminal bands have been relatively scarce. So, while Phil Lesh has played with Dickey Betts on several occasions and The Dead and the Allman Brothers Band co-headlined a night at George, WAs Gorge Amphitheatre in 2004, the last time Gregg Allman and Bob Weir played side-by-side was at a San Francisco Gibson Guitar back in the 1990s. Last Friday, however, Weir and Allman took the stage together at Camden, NJs Tweeter Center during RatDogs tour with the Allman Brothers Band. Partway through the Allman Brothers Bands closing spot Weir and RatDog drummer Jay Lane emerged for a version of Franklins Tower, one of the few numbers both units play with regularity. During RatDogs set Derek Trucks also added guitar to the popular set-closing segue China Cat Sunflower and I Know You Rider, while the evenings opening act, Keller Williams, appeared on the Beatles Come Together.

The jam session was the highlight of a collaboration-heavy week for the two groups. Last Wednesday Warren Haynes, who toured with Weir in the Dead in 2004, played with RatDog on Uncle John’s Band at Burgettstown, PAs Post-Gazette Pavilion, while RatDog saxophonist Kenny Brooks sat-in with the Allman Brothers Band on ‘Desdemona’ and ‘You Don’t Love Me.’ Then, on Saturday, Steve Kimock, who is subbing for Mark Karan in RatDog, played with the Allman Brothers Band on Dreams at Bushkill, PAs Mountain Laurel Center. Finally, last night, RatDog keyboardist Jeff Chimenti played on Whos Been Talking with the Allman Brothers Band, shortly before Kimock and Lane helped the Allmans close their set with Mountain Jam.