With 35 albums to their name, the Fatback Band isn't the hit-making machine it used to be during the 1970s and 1980s. But for an object lesson in funk music made the old-fashioned way, look no further. Many a dance and R&B record has been souped up with a Fatback sample or two, but the Fatbacks themselves belong to that mysterious era before sequencers and samplers were invented, and they still do everything by hand.

Goaded on by drummer and MC Bill Curtis, who is forever urging everybody to clap their hands and "git funky", they roll out riffs, chants and grooves with the unstoppability of an enormous turbine. The music is nailed to the floor by bassist Johnny Flippen, a Barry White-sized figure who looms over his compadres while his fingers thump out patterns so solid you could run freight trains along them. Diminutive guitarist Johnny King maintains a ceaseless flow of slippery rhythm chords and sly funk licks without once moving from the spot or changing his expression, while Gerry Thomas offers a guided tour of his splendid collection of antique keyboards.

Add a couple of horns and a battleship-sized soul diva, and voila! You are Fatbacked-up. Their best-known hits are the ones trailed on their posters. I Found Lovin' gets the medallion-man faction of the crowd throwing their arms in the air, while Curtis hurls himself into a funk frenzy on the drums during Wicki Wacki. Bus Stop is a full-scale dance routine, with the crowd shuffling back and forth in time to the band's "Four to the front . . . four to the back" commands. Spanish Hustle and Backstrokin' also get an airing.

When the band stray into less familiar material and start plugging albums nobody has heard of, the music lapses into tragically insipid soul-funk. Still, for a bit of a knees-up washed down with a few dozen alcopops, it's just the job.

· At the Big Chill festival, Eastnor Castle, August 5. Box office: 020-7 392 9180.