The tape was made by an amateur at a church fete in Woolton, Liverpool. Sotheby's is auctioning it in September. Lennon, then 16, sings Elvis Presley's 'Baby Let's Play House' and Lonnie Donegan's 'Puttin' On The Style'.
Bob Molyneux locked the tape away for 30 years, but now says: 'I think it should be shared.'
Among the crowd was 15- year-old Paul McCartney, who got into conversation with Lennon. This led to them forming the Beatles.