There was this Picasso print on the wall of an old man playing a guitar. I looked at it all week and towards the end of the week I thought what chords he playing? I’m a guitar player, what is he playing? I noticed he had two fingers here. So I thought I’d try and see what the chord is, and if it sounds any good. Ooh that’s nice. So then I tried to use that as inspiration, and tried to write a song that only used two fingers.”

• Paul McCartney, Parkinson 1999