Robert Plant headlined a charity gala at New York City's Beacon Theatre recently, but he was not the only star. Rock luminaries like Ann & Nancy Wilson, Sheryl Crow, Jimmie Vaughan, Doyle Bramhall II, and Billy Gibbons joined him. How former David Letterman announcer Alan Kalter made it on stage is anyone's guess, but his presence was a surprising treat. Here's one fan's capture of Feelin' Alright.