The song, Radhe Shaam, was originally recorded in 1968 at Trident Studios in London, where Harrison and Starr were working on The Beatles' classic Hey Jude. Broadcaster and journalist Suresh Joshi was also at Trident, working on the soundtrack to a documentary, and the two Beatles offered to play on the song.
“I stood out like a sore thumb... we started talking about philosophy in general," says Joshi. But he bonded with Harrison, whose trip to India earlier that year had opened his eyes to Indian music and culture, and later introduced him to legendary sitar player Ravi Shankar.
The master tape was found in Joshi's attic in Birmingham after a neighbour called in to check on him during lockdown and discussion turned to The Beatles. Rescued, restored and digitised, the song was given its first public airing at Liverpool's Beatles Museum this week.
Beatles Museum manager Paul Parry tells the Liverpool Echo that Radhe Shaam is "absolutely amazing", and that the drums and guitars are "unmistakably" the work of Harrison and Starr.
Also featured on Radhe Shaam is Indian classical musician Aashish Khan - who also contributed to Harrison's Wonderwall Music album - but the recording never saw the light of day.
"Time had gone on, The Beatles were breaking up and had various problems, so no-one wanted to [release it]," says Joshi. But now it's getting a proper release, with proceeds being donated to charity.
"Leave it to humanity, that's what George wanted to do," says Joshi. "I hope the fans will love it."