April 1977 -  Unknown to many fans of the rock group Led Zeppelin, its members were in the New Orleans area last week, attending a masquerade birthday party given for manager peter Grant. The four members of the British blues-rock ensemble, responsible for the rock classic, 'Stairway to Heaven', among many other songs, flew into the city via their private jet and were taken from the airport to the French Quarter's Maison Dupuy. They changed into their costumes and were photographed by Maison Dupuy manager Eddie Tresch. In the photo at left, lead singer Robert Plant signs another autograph, this one for the hotel's guest register. At right, the group's lead guitarist, Jimmy Page, talks with Mary Serpas, who furnished the guide of all the information of Led Zeppelin's visit. The group will be performing in concert at the LSU Assembly Center in Baton Rouge Thursday, May 19. However, this concert is already what most Zeppelin concerts become - an early sellout.