After Fleetwood Mac fired Lindsey Buckingham in January 2018, he blamed Stevie Nicks for his dismissal. He alleged Nicks gave the other band members an ultimatum: either he goes or I go. They decided to kick him out.
This song finds Buckingham bitter at being cast out of Fleetwood Mac while they embarked on their 2018-2019 swan song tour.
Buckingham recorded the track for his 2021 self-titled solo album. "Swan Song," along with another Lindsey Buckingham tune, "Power Down," incorporates uncharacteristic electronic drums and computerized backing vocals. "I wanted to do two songs that felt like a pair," he explained to Uncut magazine. "Those two were done with the same mindset, built for a drum loop, built off the same idea of a background vocal, and suddenly, subject-wise, built off of a certain idea of relationship challenges. So yeah, it all grew out of loops. I sensed right away that because I was making something that was a little more poppy than I'd done in a while, that these would be in a way the counterpoints to that poppiness."
Buckingham fashioned "Swan Song" from a demo he'd recorded two decades earlier. Having forgotten about it, he rediscovered the track and embellished it with modern electronic elements.
When Buckingham released the eponymous record on September 17, 2021, he credited himself as the sole writer of "Swan Song." Two months later, it was brought to his attention that the tune borrows extensively from "Mind's Eye," penned by Blinker The Star's Jordon Zadorozny and Medicine's Brad Laner in 2000. The track came from a Los Angeles studio session Buckingham did with Zadorozny and Laner, who afterwards handed the then-Fleetwood Mac guitarist a CD of songs they'd written, hoping he'd cover one of them. Buckingham realized that when he'd rediscovered the tune on the CD, he'd forgotten he didn't actually write it. On learning of his mistake, he paid Zadorozny and Laner a flat monetary sum and provided them with co-writing credits and a portion of publishing for his song.