In London, amidst the roar of red buses and black cabs, a new sound is stopping people in their tracks:
Thirty pianos are scattered across the city for the next three weeks - all part of a project to get people together, for impromptu sing-a-longs.
"What we want people to do is throw their inhibitions to the wind," said organizer Collette Hiller.
For Hiller, finding 30 pianos - donated or bought on Ebay - and moving them around London was surprisingly easy.
The hard part was cutting through all the red tape.
"There's a small tree's worth of planning applications for each piano," she said.
One of the biggest challenges will be keeping the keys dry.
London is famous for its downpours, so it's just a matter of time before this adventure turns into "Singing in the Rain." Fortunately, there's a plastic tarp for each one.
Sturdy locks and neighborhood "friends" also keep them safe.
"I'm surprised it ain't been vandalized, to be quite honest, already!" said Kailey Whitman.
Even more surprising are the pianos' effect on Londoners, who are not known for talking to strangers.
"People are quite reserved, aren't they? They just sort of go about their business," said Celia Lyons.
The pianos may be changing that.
Talent and skill level are irrelevant: All you need are fingers to pound out "Row, Row, Row Your Boat."
The ivories have struck a chord in London, and are even being hailed as a solution to the recession blues.
"This is what you need in a credit crunch," said Veronica Cecil. "You need everybody to realize the pleasures of life are free."
Even if those pleasures are sometimes a little out of tune.
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