“Sob Rock,” an album bloated with signifiers but light on hooks, uses the idea of nostalgia to sell new collectibles from John Mayer, the brand.“Sob Rock,” an album bloated with signifiers but light on hooks, uses the idea of nostalgia to sell new collectibles from John Mayer, the brand.Read MorePop and Rock Music, Advertising and Marketing, Mayer, John, Sob Rock (Album)