The Chemical Brothers, Olympia, London

From the balcony above, the 10,000 people at The Chemical Brothers' biggest ever gig look as if they're at a steamy rave, or the sort of 1960s happening the Olympia's cavernous space once attracted. The last time it was used as a venue a decade ago, the Brothers were at the cutting edge. Their big beat sound, matching breakbeats with cresting house keyboards, ruled the mid-1990s. Their great second album Dig Your Own Hole (1997) added the psychedelic experiments that acid house's name had always promised.

Like their sometime collaborator Noel Gallagher, they never found another idea. But they've retained greater pop resource, creating striking singles seemingly at will, and a deep understanding of how to make dance music a visual spectacle. And so here they still are, hitting another popular peak, for a genre that's supposed to be dead.

Tom Rowlands and Ed Simons, the one-time mediaeval history students who became club culture millionaires, are, as usual, rarely visible as they anonymously trigger storms of sound and light. In this they resemble Pink Floyd, and vintage acid-head kaleidoscope visuals confirm their interest in that era. When a vicious clan introduces bursting liquid visuals and the joyous surge of "Saturate", there are hints, too, of the primitive, idealistic early electronic records the Brothers once studied, as they forged their modern high-water mark. The voice of New Order's Bernard Sumner and a burst of Primal Scream's "Movin' On Up" during "Out of Control" nod to later inspirations. In the ongoing dialogue between dance, music and drugs, the Brothers are still history students.

For all its steamroller efficiency, their two-hour set seems more raw and home-made than slick. A great blinking eye is 1930s surreal, not 2008 digital. Then there's the yellow-toothed clown who appears to demand us to "Get yourself high" – advice you'd regret on his reappearance an hour later, growling: "You are all my children now!" The many people filming the show on their mobile phones instead of dancing suggests, anyway, that chemicals no longer rule the Brothers' world.

But the musical dynamics that ecstasy revealed still underpin every second. The crowd's hands are raised before the bee-buzz intro explodes into "Hey Boy Hey Girl". The way the dive-bomber shriek of "Believe" coalesces into a wholly enveloping sound as lights urgently strobe remains a sensory blast. The soaring jet-engine roars that the Brothers still love fill this aircraft-hanger space. The dry synth-drum cracks that resonate through it show the sonic precision which sets them apart.

They close with a perfunctory "Block Rockin' Beats", then "Chemical Beats", the 1994 EP track that began this whole trip. That it doesn't sound dated is in many ways a defeat for this one-time future sound. But being cutting-edge doesn't matter, when you make such imperishable pop.