At this point in its career, what more can be said about Rush? More specifically, how do you sum up its 40-plus years career? Perhaps the chorus of new single "Caravan" says it best: "I can't stop thinking big." The Canadian power trio basically invented space-prog, a genre that's inspired legions of musicians and sci-fi geeks the world over. This current tour features Rush performing 1981's Moving Pictures in its entirety — yes, that's the one with "Tom Sawyer" and "Limelight" — and comes hot on the heels of the successful documentary Rush: Beyond the Lighted Stage. "Caravan" is due to appear on a forthcoming new album, Clockwork Angels, and it features some killer, funk-inflected bass and raucous guitars.