The pianos are dotted around various locations including the bus station
Street pianos are to be placed around Bath in support of the city's International Music Festival.
Eleven of the instruments will be in a range of locations including Bath Abbey and the city's bus station.
Play Me, I'm Yours, is part of a wider international project which has already featured in New York, Barcelona, Sao Paulo and Sydney.
That project was in Bristol in September 2009 where pianos were placed in locations such as Queen Square.
Play Me, I'm Yours has been touring internationally since 2008 and has seen street pianos also appear in Pecs in Hungary, Cincinnati and San Jose.
In the UK, they have also featured in London, Belfast, Blackburn and Burnley.
Nod Knowles, from the Bath International Music Festival, said the pianos would give "everybody a chance to play".
"It's such a wonderful thing," he told BBC Bristol. "They installed the pianos yesterday [Tuesday] and one of them is in the abbey churchyard which is just near my office.
"The moment it was in people were sitting down and playing on it.
"I had no idea how many people could play or wanted to play the piano - it's fantastic!"
You will find the pianos at: Bath Abbey, Bath Central Bus Station, City of Bath College, Green Park Station, Milsom Place, Riverside Youth Centre, Royal Crescent Hotel, Royal United Hospital, Southgate Marquee and YMCA.
The Bath International Music Festival runs from 26 May until 6 June - when the pianos will also be removed from the city's streets.