Led Zeppelin‘s Robert Plant and Black Sabbath‘s Tony Iommi is one of the highlights of a charity auction taking place next month.The charity event put on by Julien’s Auctions will benefit MusiCares, the charitable foundation which provides aid to artists and music community professionals in times of need.Taking place on September 9 live in Beverly Hills and online at juliensauctions.com, with advance online bidding starting on August 17, some of the items up for grabs include a Gibson SG