A unique demo of the Beatles playing It's For You (1964) has been rediscovered.
The acetate disc was found in a collection of demo recordings of fellow Liverpudlian Cilla Black, which her family took to be appraised at Liverpool Beatle Auctions.
The band wrote the song for Cilla, who was a close friend - she was a cloakroom girl at the Cavern Club.
Her version charted at number 7 in the UK in 1964.
This is the only known recording of the Beatles performing the track.
Stephen Bailey, manager of the Liverpool Beatles Shop, told the Telegraph newspaper: "We got to the last one, and as soon as I heard it, I thought, 'Oh God, that's not Cilla Black. It's Paul McCartney.
"I was shaking with excitement and speechless. I realized that this was the long lost Beatles demo disc from 1964, and I was probably one of the few people to have seen and heard it in over 50 years."
"Apart from a few crackles, which you get with acetates, the quality is fine. It's a wonderful recording."
The lot is expected to make around £15,000-20,000 ($19,795-26,394), a sum it will probably surpass.
Earlier this year a 1962 Beatles demo sold for £77,550 ($109,778), having been offered with a reserve of just £10,000 ($13,178).
The fact that this is an unreleased recording will make it especially valuable to collectors.
The lot will cross the block on August 27.
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