An unheard track by former Beatles Sir Paul McCartney and Sir Ringo Starr is to be sold at auction.
Angel In Disguise is one of only a couple of songs co-written exclusively by the remaining members of the Fab Four.
The pair recorded the demo for Sir Ringo's 1992 solo album Time Takes Time, but it did not make the LP.
The cassette is now being sold by former Radio Luxembourg DJ Tony Prince and is expected to fetch up to £20,000.
A quarter of the profits will be donated to the NHS Charities Together Covid-19 Urgent Appeal, while the rest will go to Prince's United DJs radio station project.
Two versions of the track appear on the tape; a rough demo with Sir Paul singing, and a more fleshed out take with the drummer on lead vocals, with additional instruments and backing vocals.
A demo of another Sir Ringo track, called Everyone Wins, also appears on the cassette, which will go under the hammer at Omega Auctions' online sale on 19 May, alongside other memorabilia.
The sticksman was previously credited as a co-writer on a track called Really Love You, which appeared on Sir Paul's 1997 album Flaming Pie.
Chris Shaw, host of The Beatles podcast I am the Egg Pod, told the BBC that while the new discovery could raise the spirits of some quarantined Beatlemaniacs, the track itself is unlikely to appear on any 'best of' collections anytime soon.
"Any newly discovered Beatles-related songs are always exciting for fans, and the Starr/McCartney credit makes this all the more alluring," he said.
"However, the fact that Angel in Disguise was rejected suggests that it may not be the best song in the world. Sometimes these things are better left as tantalising mysteries."
The sheet music, which appears to only credit McCartney as the writer, shows the lyrics include: "My name is Ritchie / Let me look into your eyes / Don't be afraid I'm just an angel in disguise".
Ritchie, of course, referring to Starr's actual given name, Richard Starkey.
While he sang on almost a dozen Beatles songs, including Yellow Submarine and With a Little Help from my Friends, the 79-year-old was only credited with having written two by himself; Octopus's Garden and Don't Pass Me By.
Starr co-wrote several others though alongside McCartney and the late John Lennon, including What Goes On from their 1965 album Rubber Soul.
His 20th solo album, What's My Name, was released late last year, and featured a Lennon-penned track, Grow Old with Me.
"It's fantastic to be able to bring to the market a previously unheard and unreleased track," said Omega auctioneer Paul Fairweather.
"We think the track certainly had enough about it to be included in the album and I am sure if Paul was to release this himself it would certainly prove a hit with fans."
Also included in the sale are a collection of letters and documents sent to Tony Prince following the death of Beatles-hero Elvis Presley in 1977, after he broke the news live on air. As well as autographs by Paul and Linda McCartney and a jacket owned by Eric Clapton - one of the few outside musicians to ever appear on a Beatles track (While My Guitar Gently Weeps).