The Rock and Roll Hall of Famer died Wednesday morning at the hospital following a "short illness" at age 79.
Christine's family has asked for privacy and for people to keep her "in their hearts and remember this life of an incredible human being, and revered musician who was loved universally."
The outpouring of tributes Wednesday only served to validate that statement.
Fleetwood Mac was among the first to share a tribute to McVie, who first joined the group in 1970, two years after marrying cofounder and bassist John McVie.
"There are no words to describe our sadness at the passing of Christine McVie," the band said in a release. "She was truly one-of-a-kind, special and talented beyond measure. She was the best musician anyone could have in their band and the best friend anyone could have in their life. We were so lucky to have a life with her. Individually and together, we cherished Christine deeply and are thankful for the amazing memories we have. She will be so very missed."
Christine's bandmates chimed in soon after, with Stevie Nicks writing that she was ready to fly to London as soon as she learned last weekend that her "best friend in the world" was ill.
Fleetwood Mac cofounder and drummer Mick Fleetwood added that he "will miss everything about" Christine after making music with her for some 50 years.
Crowded House's Neil Finn, who toured with Fleetwood Mac as a singer-guitarist, added that Christine was "a unique and soulful woman, supremely gifted songwriter and a warm and wonderful friend."
Another one-time member of Fleetwood Mac, Mike Campbell, added that there was "no one like [Christine] in the universe." He added a recollection about a compliment Christine once paid him during rehearsal and concluded, saying, "I've never met anyone with such an angelic aura. Always so kind to everyone."
Heart's Ann Wilson called Christine "a gem" and said that Fleetwood Mac's "Over My Head" has long been one of her favorite songs.
Bob Seger added that Christine was as big a part of Fleetwood Mac's incredible success as anyone.
Kiss's Paul Stanley wrote that Christine was fully deserving of her "Songbird" nickname.
Sheryl Crow wrote that the "world feels weird without her here. What a legend and an icon and an amazing human being."
Check below for more reactions as they arrive. Rest in peace, Christine McVie.