Fleetwood Mac keyboardist and singer-songwriter Christine McVie died at age 79 on Wednesday, her bandmates announced.
“There are no words to describe our sadness at the passing of Christine McVie. She was truly one of a kind, special and talented beyond measure,” the band said.
“She was the best musician anyone could have in their band and the best friend anyone could have in their life.”
McVie married bass player John McVie and joined Fleetwood Mac in 1971, when the band experienced a tumultuous period after the departure of founding member and lead guitarist Peter Green.
Her first contribution to the band came in that year's album Future Games, which showed the beginning of the band moving away from the blues-inspired music on which they built their first period of fame.
It would be another four years until Fleetwood Mac became a pop rock powerhouse with the introductions of singer Stevie Nicks and guitarist Lindsey Buckingham.
"A few hours ago, I was told that my best friend in the whole world since the first day of 1975, had passed away," Nicks wrote in a handwritten note posted on Twitter.
"I didn't even know she was ill... until late Saturday night. I wanted to be in London; I wanted to get to London - but we were told to wait.
So, since Saturday, one song has been swirling in my head, over, and over and over. I thought I might possibly get to sing it to her, and so, I'm singing it to her now."
Photos in the tweet show the handwritten lyrics of the song she thought of and an image of her and McVie.
McVie's divorce from the bass player was part of a period of intense break-ups in the band, which were ultimately inspired to produce the chart-topping album Rumours in 1977.
She wrote some of the band's highest-charting singles including Say You Love Me, Don't Stop, You Make Loving Fun, Little Lies, and Everywhere.
McVie left the band in 1998 but returned in 2014.
Mick Fleetwood also posted his condolences on Twitter, "I will miss everything about you Christine McVie."
In 2017 she and Buckingham released the album Buckingham-McVie.
An auction of the band's items — including a jewel-encrusted skeleton key necklace worn by McVie — is due to take place at Julien's Auction House in Beverly Hills on December 3 and 4.
