McCartney explained that while living lockdown life on his Sussex farm with his family, he kept himself busy working on some music in his home studio. One day he returned to an unreleased track from the early '90s, "When Winter Comes," and crafted a new passage for the song, creating both "Long Tailed Winter Bird" and "Winter Bird / When Winter Comes
," which bookend the album.
After completing those tunes, McCartney wondered what to do next. "I had some stuff I'd worked on over the years but sometimes time would run out and it would be left half-finished so I started thinking about what I had," he explained. "Each day I'd start recording with the instrument I wrote the song on and then gradually layer it all up; it was a lot of fun. It was about making music for yourself rather than making music that has to do a job. So, I just did stuff I fancied doing. I had no idea this would end up as an album."