CHEMICAL BROTHERS

Early in the evening, someone thought they had a better word than "electronica" to describe the Chemical Brothers. "Rhythmotech!" the woman said firmly, her eyes twinkling behind her little oval framed glasses. "Listen to it: Rhyth-mo-tech! It's so ... all-encompassing!"

Not as marketable as electronica, perhaps, but as applied to a group like the Chemical Brothers, a compound adjective of rhythm and technology makes perfect sense. Musical mad scientists, the Chemical Brothers should have been wearing lab coats during their Wednesday night show. There was certainly enough Frankensteinian lighting to match the duo's synthetic music. And there wasn't a guitar or bass in sight -- everything was in the can.

Or in the drum -- the 55 gallon variety. Even more significant than the Brothers' weird-science sounds was their proclivity for primal beats. Songs didn't stop so much as evaporate or merge into one another, carried by tracks as constant as a heartbeat. Small melodic remarks were punctuated by shotgun blasts, sirens, whistles and explosions, all right on the metronome mark.

The cavernous Union Station functioned as a huge, high-ceilinged echo chamber, and each sound ricocheted like a marshmallow cannonball. The Chemical Brothers' music is not about delicacy and distinction, it's built to careen at high speed and splatter like an aural pie in the face. And the bottom rumbled with such extreme prejudice that clothing vibrated like a second snaredrum skin across every square inch of your body. Who could possibly be paying attention to the pitch?

Certainly not the audience, which danced either as a mob-of-one -- fingers pointing, torsos undulating, heads bobbing, collectively caught up in the k-hole -- or individually, locking, breakdancing, aerobicising or just vibrating in place. Some danced as if they'd seen Rerun on "Good Times" one too many times, but it would have had to have been reruns of Rerun -- most were simply too young to have been there the first good time around.

The Brothers themselves didn't move much at all -- but they were still treated like rock gods by the jam-packed mob. With only a few hand waves, they were the heroes of the dance. And it wasn't hard to imagine that they came up with this music so they'd have a way to get invited to the dance in the first place.