“M” reports:
The artist Luke Jerram is responsible for the placing of 30 pianos around London.
Every piano has laminated music sheets for those rainy days and each is painted with a theme relating to the part of London it is in, along with the invitation ”play me, I’m yours”.
For more info, check out these links:
http://www.viewlondon.co.uk/whatson/street-pianos-london-feature-3079.html
http://news.bbc.co.uk/1/hi/england/london/8114859.stm
You can find the pianos at popular locations around London such as Oxford street, Carnaby Street, Portobello road and Leicester Square.
We found one at the British Library:

Street Pianos London lasted from the 19th June to 13th July 2009, so we just caught it!