It’s unclear exactly when George Harrison first had the idea of asking his friend Eric Clapton to play on “While My Guitar Gently Weeps.” To all appearances, it was an entirely spontaneous invitation offered as George and Eric drove from Sussex to London today — they often commuted to work together to take advantage of the MLG (Multiple Lead Guitarist) lane.

Bob Spitz’s The Beatles quotes Clapton as saying “We were in George’s car … and he said, ‘Do you want to come and play on this record?’ ” When Clapton worried how the other Beatles would react, George said “It’s nothing to do with them. It’s my song, and I’d like you to play on it.”

This was a smart move on George’s part. Over and above Clapton’s guitar prowess, his presence forced the other three Beatles to behave, as they generally did with outside musicians around (see also: Billy Preston). They all put in more effort than they usually did on George’s songs, and George himself was inspired to give what many consider the vocal performance of his lifetime.

As for that guitar part … I’m no Clapton partisan. He’s a gifted technician who has often made questionable artistic choices. But in this case he killed it; his contribution lifted George’s song to a whole other level.

No photos seem to exist of Clapton’s Beatles recording session, which was sort of a secret, and no credit appeared on the album. In its White Album review even Rolling Stone could only speculate on whether it was him playing; he was sort of a spectral presence hovering above the song.

Back then people used to spraypaint “Clapton is God” on the walls. Here in 2018, Rolling Stone confirms that he will be releasing a Christmas album called Happy Xmas. And still his guitar gently weeps, but this time from sheer embarrassment.