Sir Paul McCartney's first guitar is going up for sale later this month.
Sir Paul played his first chords on the Rex acoustic
The Rex acoustic guitar is expected to fetch more than £100,000 at Cooper Owen's Music Legends auction at Abbey Road Studios in London on 28 July.
Sir Paul learned his first chords on the instrument, which was owned by his best school friend in Liverpool, Ian James.
Mr James, 64, who lives in Ormskirk, Lancashire, is selling the guitar to help fund his retirement.
The instrument is accompanied by a letter of authenticity from the former Beatle which says: "The above guitar belonging to my old school pal Ian James was the first guitar I ever held.
The guitar comes with a letter of authenticity from Sir Paul
"It was also the guitar on which I learned my first chords in his house at 43 Elswich Street, Liverpool 8."
Sir Paul mentioned Mr James in "The Beatles", a biography by Hunter Davies.
In the book, he described playing the guitar for a 16-year-old John Lennon at a fete in St Peter's Church Hall in Woolton, Liverpool, in July 1957.
Lennon was playing there with his band, The Quarrymen, and McCartney played some songs for them - convincing Lennon to let him join the band.
McCartney said: "I showed him a few more chords he didn't know.
"Ian James had taught me them, really. Then I left. I felt I'd made a good impression, shown them how good I was."
Mr James, 64, is a retired father-of-three living in Ormskirk, Lancashire.
He is selling the guitar to help fund his retirement.
The lot also contains a photo taken by Sir Paul of a young Mr James playing the guitar in 1957 and a photo of the former Beatle playing the guitar in his office earlier this year.