As marathons go, this one will be harder on the hands than the feet.
Stephen Ridley, 23, from Hackney plans to play a piano continuously for 24 hours outside Tate Modern starting at 3pm on Friday.
He will use one of 50 “Golden Pianos” distributed across the capital as part of the Play Me, I’m Yours arts project.
Mr Ridley left his job as an investment banker last year to become a street musician and now travels the world, playing classical, jazz, pop and blues.
He is raising money for Cancer Research UK after his best friend’s mother was diagnosed with breast cancer.
“The most I’ve played for before without stopping is eight hours and I was exhausted then,” he said.
Luke Jerram, the artist behind the piano project, which he has taken around the world, said: “It’s amazing to watch how the pianos get used by different people and the stories that come out of them.
“A couple of years ago a couple met at one site, fell in love and when they got married, they invited the piano to the wedding.”
To donate, go to www.justgiving.com/Stephen-Ridley