THE BOTTOM LINE: In mid-megavolt Zoo TV tour, U2 switches channels with an introspective new album.
How do you wind down from one of the most electrifying rock shows ever staged? If you're U2, the indefatigable Irish quartet, the answer is you don't. Riding the wave of its audacious 1991 album, Achtung Baby, the group has spent the past 15 months hop-scotching the globe with the Zoo TV tour, a futuristic, high-voltage extravaganza that has packed stadiums from Berlin to Los Angeles, and is scheduled to end in Australia next November. But just when most...