Composer Andrew Lloyd Webber and lyricist Tim Rice of, first, the pop-rock musical Jesus Christ, Superstar and, now, Evita are a couple of pop-art geniuses; what they lack is talent….

[Eva Peron's life] is certainly the stuff of opera, and opera is just what our heroes have propsed: great sumptuous orchestrations played by the London Philharmonic, funny off-key recitatives, Menotti-modern-opera scenes, choral madrigals, frenzied chants, and Latin lamentations, as well as heavy-beat rock music, much of it with a greasy sort of Latin overlay.

But is all this panoply mere show without substance? So it seems; one looks in vain for content. In the case of Superstar, Webber and Rice had some familiar dramatic material to work with. Here they need to sort it out themselves, and they don't. Politics gets short shrift, and so they miss out on the great background story of how a populist, working-people's...