Derry's two cathedrals join UK-wide Olympic bell ring
The bells on Londonderry's two cathedrals are to ring out in harmony as part of a UK-wide celebration of the London 2012 Olympics.
Everyone has been invited to ring some kind of bell on Friday morning.
The project is the idea of Turner prize-winning artist and musician Martin Creed.
It is called: "Work No. 1197: All the bells in a country rung as quickly and as loudly as possible for three minutes at 08:12 27th July."
Everyone from enthusiastic children with hand bells, bicycle bells and doorbells to experienced change ringing experts of tower bells is invited to join in.
To get involved all individuals, communities and organisations are encouraged to register at the project's website .
The ringing marks the first day of the London 2012 Olympic and Paralympic Games.
"It could be a brilliant and amazing sound," said Mr Creed.
"Whether you've got a bicycle bell or something much grander, this is a opportunity to mark a once in a lifetime occasion. This is wonderfully innovative project and I am delighted to support it."
Thousands of people have already registered to take part, and everyone who signs up will be able to download a ringtone by Mr Creed, Work No. 1372, which features 28 different bell sounds.
All the Bells will be broadcast on various BBC television and radio programmes.