We live in a time when the White Stripes are tabloid fodder and minor garage-punk acts such as the Hives plays 4,000-capacity venues instead of dingy basements. The boundary between alternative and mainstream music seems non-existent, dismantled through the 1990s as the Stone Roses, Nirvana, Blur and Oasis rose to fame.

But at All Tomorrow's Parties, the festival held on the Sussex coast, Oasis are considered "fools" and the Hives "losers". The line-up, chosen this year by the fiercely independent American rock band Shellac, is defiantly obscure, peppered with such flummoxing names as Robbie Fulks, Flour and Three Second Kiss. Travis and Stereophonics don't even make it into the pub DJ's record box.

If the festival has a problem, it is an air of self-righteousness born from a delight in being different. Last year this spilled on to the stage, resulting in three days of cerebral, distinctly unenjoyable live performances. This year promised to be little different, judging by the earnest descriptions of the bands in the festival programme: "In their continued exploration of their music, they have experimented, discovered themselves and continued the experiment so as to avoid the stagnation of complacency," is how Shellac's Steve Albini captures the thrill of Wire.

So it was delightful to hear country singer PW Long announce, "My dick is as hard as Chinese arithmetic," to watch erstwhile Pixies drummer David Lovering demonstrate how a gherkin glows when an electric current is passed through it, and to discover the Upper Crust, a dreadful light-metal band from Boston who dress and talk like aristocratic 17th-century English fops.

All humourlessness was confined to the programme; even the Fall's cantankerous Mark E Smith proved cheery, spending his headline slot making silent jokes about his young bassist's long hair.

Shellac themselves played each day of the festival, and although the first set was marred by shoddy sound, the third was musically pristine and highly entertaining. Between songs the trio held their traditional question-and-answer sessions, Bob Weston invited people to visit their hair stylist, and Albini spoke heartwarmingly of the sense of community he misses in alternative music. It is this sense of community that All Tomorrow's Parties seeks to instil in festival-goers, and no one caught that mood better than Kim and Kelley Deal of the Breeders, who grinned and teased each other through a raucous, invigorating set and spent every night getting drunk with the punters in the pub.

· All Tomorrow's Parties is repeated at Pontins, Camber, from Friday until Sunday. Details: www.alltomorrowsparties.co.uk