With the stage so dark, it's impossible to tell when the duo actually arrive - but one moment it's empty, save for a glut of very expensive technical equipment, and the next, two shady figures are intertwined in the wires and faders, crouched over a mixer like a pair of schoolboys playing at being mad scientists, huddled together, twiddling knobs and cooking up a party.

Opening with Hey Boy, Hey Girl, the beat drops and the arms of 5,000 sweaty people go up in the air. Strobe lights crisscross above the crowd, and dry ice continually shoots out from either side of the stage. As the duo have roughly the same amount of charisma and stage presence as a bloke fixing your bike down Halfords, it's no wonder the lights are on the crowd instead of the stage. Occasionally, one of the Brothers disappears entirely, but not that anyone would notice as the cheesy banging bhangra of Galvanise takes hold and the visuals provide a colourful backdrop. But after the initial sonic rush and slightly nauseating bass that makes eardrums rattle and bodies quiver, it all becomes rather annoying, and as the duo take Brixton on a high-speed journey through drum and bass, trance and euphoric house it's enough to give anyone motion sickness.

Building it up and crashing it back down again every five minutes, the Chemicals provide more drops than Beachy Head. It's the sign of a one-trick pony, and a lame pony at that. Is that the glue factory we hear calling?