Thousands of bells have rung out across the UK to mark the official start of the Olympic Games.
Big Ben rang 40 times in three minutes, while church bells, doorbells and even bicycle bells all joined in the performance.
The event was triggered by the firing of cannon on HMS Belfast.
Turner Prize-winner Martin Creed dreamed up the idea, calling it "a brilliant and amazing sound" and a "once-in a lifetime" performance.
Some participants had a narrow escape, however, when a bell being rung by culture secretary Jeremy Hunt flew off its handle.
Mr Hunt looked horrified as the brass bell sailed over the heads of a group of women, and was caught on camera saying: "Oh, oh dear! Are you all right? Health and safety!"
Entitled Work No 1197: All the bells in a country rung as quickly and as loudly as possible for three minutes, the project aimed to set a new world record for the largest number of bells being rung simultaneously.
"It's a piece of music for a special occasion," Creed told BBC Breakfast.
"Bells are the loudest acoustic instrument - that's why they're used by churches."
Ruth Mackenzie, director of the London 2012 Festival, joined the 300 children, sea cadets, brownies and Town Criers on board HMS Belfast.
"I can scarcely hear a thing," she said immediately after the event.
"A young woman next to me said it was like a workout. It's good training - perhaps we should do this every day at 08:12."
She added: "I'm most proud of Ben Ben for leading us - it's the first time since 1952 that Big Ben has departed from schedule."
Mackenzie was joined by Honey Kalaria, a Bollywood ambassador to the UK, and 45 children from her dance academy.
"Britain is such a multicultural society and has such a fantastic history, so bringing a bit of Bollywood onto HMS Belfast was a great amalgamation of the two," she said.
Thousands of people and organisations registered to take part including the RAF, the National Trust, the National Theatre, the Mayor of London, the Archbishop of Westminster and The Girl Guides Association.
The world's largest aluminium bell, which weighs 750kg and is made from the fuselage of a decommissioned Tornado fighter, was also rung at a publisher's office in London.
The Royal Navy and the Royal Fleet Auxiliary participated across the UK and overseas with as many ships, shore bases and naval establishments as possible.
In Berwick-upon-Tweed, the ceremony started with a blast on a 12ft-high Celtic war horn, while churches in the Isle Of Man and Northern Ireland all took part.
While all four parliaments in the UK, The National Assembly for Wales, Stormont, Holyrood and the House of Commons, rang in unison.
Bells were also expected to be rung around the world in countries including Australia, the US, China, Botswana and even in Antarctica.
And scientists at the British Antarctic Survey at Rothera Research Station, on Adelaide Island resorted to banging pots and pans, after discovering their base was "decidedly lacking in anything resembling an actual bell".
The event was broadcast on BBC Breakfast, Radio 4 and Radio 2 - where Chris Evans took part in the ceremony alongside Moira Stewart, Dame Kelly Holmes and Martin Creed himself.
More information is available at the All The Bells website.