A collection of every UK number one record since the singles chart began is due to be auctioned.
Elvis Presley holds the record for the most UK number ones, with 21
The musical memorabilia is owned by Stephen Hitchcock, 35, of Brighton, who has been adding to it since inheriting it from his father 23 years ago.
The 2,139 items include 78rpm, 7in and 12in vinyl singles, cassette, CD and DVD singles, and digital downloads plus an iPod Nano to play them on.
The lot has been given a guide price of between £25,000 and £28,000.
It is part of a Cooper Owen Music Legends auction being held at the Abbey Road Studios in London on 28 July.
Mr Hitchcock said: "I started buying first edition number ones every week and then, over the next ten years, updated the collection.
"I would love whoever buys it to continue the collection, or even better I would love it to go into a museum."
Mr Hitchcock's grandfather bought the first ever number one single, Al Martino's Here In My Heart, in November 1952.
The collection comes in professional DJ storage boxes.
The old 78rpm records can be played on an original Pye Black Box from 1955, which is included in the auction.
The first number one to be included as a download was Tony Christie's Amarillo from March 2005.
Cooper Owen's John Collins said: "This is probably the biggest collection of British popular music ever discovered.
"I've never seen anything as extensive... with so many rare pieces," he added.