It reveals the inspiration behind the 1967 Beatles classic I am the Walrus.

We have got bids on about 60 percent of items in the sale. They have come from all over the world -- Japan, Brazil, America and Europe.

The 'Double Fantasy' album was probably written on it. He never went out of the building for five years and we assume a lot of work was done on this piano.

For years they were believed to be missing. Then four months ago they were discovered in one of the museum's depositories, sitting in a sealed crate out in Acton.