It is Garcia. And he was the first to admit he laid a lot of eggs in his time. This is one of them, imo. No matter how much I listen with any part of my body, it doesn't lend his voice any semblance of strength or bring it into key. Whereas his advancing age and deteriating health often lent his voice some level of gravitas, here he is alternately sharp, flat and weak and whiny.
Different strokes, I suppose, but i find this to be among the absolute worst thing I've ever heard come out of the big guy... a terribly depressing portrait of a man on death's door who has lost much of his previous genius and abilities. I suspect he and the band felt much the same, as there is a probably reason it was never released before. Sometimes I just don't get the Dead Channel's programming... For example, why on earth do they broadcast so many totally inferior sounding shows when there are so many high-quality recordings out there? Some of them sound like tenth generation boots recorded from under the stage through a bag of wet rags.
Anyway, just my $.02.