Paul Williams told Songfacts
about his collaboration with Streisand on this song: "She sat down and played on a guitar, the melody for 'Evergreen' that she'd written. It was just such a beautiful melody. I said, 'There's your love song. There's the big love song.' I asked her for the melody. She put it on tape for me, and I took it home. I actually wrote that as the last thing, which I think bothered her. But all the Kris Kristofferson stuff was the first thing up on the shoot schedule. So I wrote the songs for Kris first.
You know, Barbra recorded two or three of my songs before we did A Star Is Born
. People would always ask, 'Were you nervous about writing the Streisand music?' Of course, she's an amazing talent. But to sit down and write songs and to play songs for Kris... I mean, this is the man who wrote 'Sunday Morning Coming Down
,' 'Me And Bobby McGee
.' It was wonderful. Kris was great about the songs. But the very last thing that I wrote was 'Evergreen.' I gave that to Barbra, and then hit the road and didn't look back."