10 Years of All Tomorrow's Parties</p><p>Butlins Minehead, Somerset

A decade after the All Tomorrow's Parties music festival was first formulated by Scots indie outfit Belle & Sebastian as the Bowlie Weekender, it hasn't become any easier to explain to people. In simple terms, it's a three-day event based in a traditional British holiday resort (first, Pontin's at Camber Sands, East Sussex; now, Butlins Minehead), which offers a nostalgic indoor setting and relatively pleasant chalet accomodation. Musically... well, let's just say few ATP virgins will get through their first exposure to the festival without hearing something that will astound, confuse or even annoy them intensely.

Many of the bands playing the music appreciate this themselves. "Our music makes people nauseous," noted Satomi Matsuzaki, dynamic Japanese- American singer with Californian art-pop group Deerhoof, with mock resignation as a suffering fan was dragged from the front row of her show. In fact, Deerhoof were possibly the weekend's most enjoyable act, a joyous collision of devastating bubblegum pop hooks, DIY dance choreography and a fine line in cover versions including Canned Heat's "Going Up the Country" dedicated to The For Carnation's Brian McMahan (whose band had played a gorgeous set late on the Saturday night) and the Velvet Underground's "All Tomorrow's Parties" in honour of ATP organiser Barry Hogan.

Sidelining the usual "curated" element of ATP, Hogan and his team this time chose the line-up themselves from various artists who had previously been invited to do so and acts who have played the festival on multiple occasions. Among the latter category were the two groups Hogan has described as his favourite ever at the festival: frankly crazed Japanese girl duo Afrirampo, all garage rock power and sweet, girly sing-song voices, and the cataclysmic Lightning Bolt, ending the festival late on Sunday night with the strange spectacle of drummer Brian Chippendale wearing a gimp mask and a microphone inside his mouth, and creating some truly monumental noise alongside guitarist Brian Gibson. A defining memory of this festival came as Afrirampo joined Lightning Bolt for the final song of the weekend, yelling out their vocals from a position crowdsurfing atop the heaving crowd.

Alongside such spectacles, staggering sonic invention was to be found in excess. Where Lightning Bolt play drum'n'bass disguised as thrash metal, electronic duo Fuck Buttons use the beautifully building sounds of post-rock during what was essentially a techno set, while New York art- rockers Battles were compelling but uncategorisable.

It also says much for the open-mindedness of the typical ATP fan that the weekend's most striking bands were dissected and discussed over supposedly bigger names. Friday headliners Yeah Yeah Yeahs united the crowd with a rare touch (for this festival) of real glamour, but Saturday's Breeders, Kim Deal of Pixies' other band, were mid-paced and disappointing, and instrumental folk-rockers Dirty Three (headed by Warren Ellis of Nick Cave's Bad Seeds) were an odd main stage choice while lo-fi superproducer Steve Albini's comedy rockers Shellac were tearing up the smaller room with another ATP-exclusive performance.

The rest of the bill was a catalogue of truly esoteric music from down the years, with grunge from Mudhoney, post-rock from Tortoise, psychedelic rock from Captain Beefheart's old Magic Band and more. That's why All Tomorrow's Parties is now, indisputably, the defining symbol of alternative sonic culture in the UK.

What was the most memorable arts event of 2009? In the comments form below (or via email to arts@independent.co.uk) nominate your favourite - in film, music, theatre, comedy, dance or visual arts - with a brief explanation as to why it tops your list and we'll print a selection in The Independent Readers' Review of 2009.