It’s the 50th anniversary year of the mythic Summer of Love, and Bobby, Mickey and Bill are returning to pull out all the old improvs. John Mayer fills Jerry Garcia’s shoes (ahem); Oteil Burbridge phills Phil’s (and while Oteil is no zany avant-gardist, he’s still a hell of a bassist). Let’s not kid ourselves, though: Dead & Co. is a nostalgia act. If you’re a Deadhead, this is the best thing happening this week. Otherwise, if you want live Dead, listen to Live Dead.