"Never mind that shit," says Joe Strummer, the thuggish-looking lead singer of the Clash, addressing the exultant kids yelling, "Happy New Year" at him from the teeming floor of the Lyceum. "You've got your future at stake. Face front! Take it!"

In sleepy London town, during a murky Christmas week, rock & roll is being presented as a war of class and aesthetics. At the crux of that battle is a volcanic series of four Clash concerts — including a benefit for Sid Vicious — coming swift on the heels of the group's second album, Give 'Em Enough Rope, which entered the British charts at Number Two. Together with the Sex Pistols, the Clash helped spearhead the punk movement in Britain, along the way earning the designation as the most intellectual and political New Wave Band. When the Pistols disbanded early last year, the rock press and punks alike looked to the Clash as the movement's central symbol and hope.

Yet, beyond the hyperbole and wrangle that helped create their radical myth, the Clash brandish a hearty reputation as a rock & roll band that, like the Rolling Stones and Bruce Springsteen, must be seen to be believed. Certainly no other band communicates kinetic, imperative anger as potently as the Clash. When Nicky "Topper" Headon's single-shot snare report opens "Safe European Home" (a song about Strummer and lead guitarist Mick Jones' ill-fated attempt to rub elbows with Rastafarians in the Jamaicans' backyard), all hell breaks loose, both on the Lyceum stage and floor.

Like the Sex Pistols, the Clash's live sound hinges on a massive, orchestral drum framework that buttresses the blustery guitar work of Jones, who with his tireless two-step knee kicks looks just like a Rockettes' version of Keith Richards. Shards of Mott the Hoople and the Who cut through the tumult, while Strummer's rhythm guitar and Paul Simonon's bass gnash at the beat underneath. And Strummer's vocals sound as dangerous as he looks. Screwing his face up into a broken-tooth yowl, he gleefully bludgeons words, then caresses them with a touching, R&B-inflected passion.

Maybe it's the gestalt of the event, or maybe it's just the sweaty leather-bound mass throbbing around me, but I think it's the most persuasive rock & roll show I've seen since I watched Graham Parker rip the roof off a San Francisco night club almost two and a half years ago.

I try to say as much to a reticent Joe Strummer after the show as we stand in a dingy backstage dressing room, which is brimming with a sweltering mix of fans, press and roadies. Strummer, wearing smoky sunglasses and a nut-brown porkpie hat, resembles a roughhewn version of Michael Corleone. Measuring me with his wary, testy eyes, he mumbles an inaudible reply.

Across the room, Mick Jones and Paul Simonon have taken refuge in a corner, sharing a spliff. "You a Yank?" Jones asks me in a surprisingly delicate, lilting voice. "From 'ollywood? Evil place, innit? All laid back." According to the myth encasing this band, Jones who writes nearly all of the Clash's music, is the band's real focal nerve, even though the austere Strummer writes the bulk of the lyrics. In the best Keith Richards tradition, fans see Mick as a sensitive and vulnerable street waif, prone to dissipation as much as to idealism. Indeed, he looks as bemusedly wasted as anyone I've ever met. He's also among the gentler, more considerate people I've ever spent time with.