Stevie Nicks wrote this in 1978 with the help of her friend Sara Recor, a singer and model who the song is named after. At the time, Stevie was secretly dating drummer Mick Fleetwood, who had recently divorced. A few months later, Fleetwood fell in love with Sara Recor and broke up with Nicks. He and Sara were married but later divorced.
This is a very personal song for Stevie. It is about a combination of things going on in her life, including the band, her friend Sara and her relationship with Fleetwood, but she considers "Sara" to be her alter-ego and her muse - the "Poet in her heart."
The "Great dark wing" in the lyrics is Fleetwood. He had a loud red Ferrari, and that's how Stevie and Sara used to describe him when he'd drive up.
The album was eagerly anticipated, since it followed up Rumors, one of the best-selling albums of all time. This is one of the few songs on Tusk that went over well with most listeners. Much of the double album can be described as "experimental," with a lot of songs written by guitarist Lindsey Buckingham that sounded nothing like the songs on Rumors.
This was 16 minutes long when Nicks wrote it. They had to edit it down to under 5 minutes for the album, but Stevie claimed the "real version" has about 9 more verses and tells quite a story.
In 1986, Nicks checked in to The Betty Ford Clinic to kick her cocaine addiction. She signed in using the name "Sara." She wrote a song about the experience called "Welcome To The Room, Sara" that appeared on Fleetwood Mac's 1987 album Tango In The Night.
"Sara" may have been the name Nicks gave to her unborn child before she had an abortion. In 1977, she dated Don Henley, and later confirmed that she became pregnant with his child and terminated the pregnancy. Henley spoke about it in a 1991 interview with GQ, where he stated: "I believe to the best of my knowledge became pregnant by me. And she named the kid Sara, and she had an abortion and then wrote the song of the same name to the spirit of the aborted baby. I was building my house at the time, and there’s a line in the song that says 'And when you build your house, call me.'"
Nicks wrote this on a piano, and it was very hard for Mick Fleetwood to put a drum track together for it. He used brushes to make it work.
A woman from Michigan sued Nicks when this was released, claiming she wrote a similar song that Stevie must have nicked. Even though some of the lyrics were similar, Stevie was offended by accusation and refused to settle. The other side gave up when it became clear Stevie did not plagerize the lyrics.