Revivals? So 20th Century! Give me Meta!

This article in the Sunday Times describes a fascinating shift in the commercial theater: it appears that the wave of revivals may well have crested and there are almost no good shows left to revive. With the catalog of the pop song world exhaustively exploited in jukebox shows and the field of revivals fully tilled, maybe the focus on Broadway will shift back to new musicals. Meanwhile, another peculiar recent trend is what I'll call (unless someone can think of a better term) "meta" musicals, shows which rely on references to other shows for their humor. In Philadelphia, we're getting "The Musical of Musicals: The Musical" this fall, while NY audiences are currently enjoying "Silence" at the Fringe (a show that seems to owe a good deal to "Urinetown," also a meta-musical). When a friend described "Spamalot" to me, it sounded like Meta on a Mega scale. Of course, an art work or object that makes reference to other works is nothing new -- Joyce's "Ulysses" and the films of Quentin Tarantino come to mind -- and the present is always in some sort of dialog with the past, but what's distressing about these musicals is that (at least as far as I can tell) they're largely content-free: the gimmick is the show (something James Joyce didn't have a problem with).