For all the fearful talk about what Peter Gelb will do when he takes the reins of the Metropolitan Opera in 2006, Gelb seems to have a remarkably upbeat philosophy about high culture: as he puts it, “art can be both commercially successful and artistically successful.” Of course, it’s the “commercial” aspect that worries some observers, and Gelb’s tenure at Sony Classical is an example of what many purists believe is blatant commercialism at the expense of true artistic success.