Elton John: The singer posted a photo of himself with Michael on Instagram with the caption "I am in deep shock. I have lost a beloved friend - the kindest, most generous soul and a brilliant artist. My heart goes out to his family, friends and all of his fans."
Madonna: "Farewell My Friend! Another Great Artist leaves us. Can 2016 Fuck Off NOW?"
Singer Bryan Adams: "RIP George Michael. I can't believe it. Such an incredible singer and a lovely human being, far too young to leave us."
Queen guitarist Brian May: "I just saw the sad news about George Michael as I was heading for bed. I don't have the words. This year has cruelly taken so many fine people way too young."
Singer Meat Loaf: "God Bless George Michael, Say a prayer for him . A nice human."
Pop Band Duran Duran: "2016 - loss of another talented soul. All our love and sympathy to @George Michael's family."
Musician Gary Numan: "Oh no. George Michael RIP."
Talkshow host Ellen DeGeneres: "I just heard about my friend @GeorgeMichael's death. He was such a brilliant talent. I'm so sad."
Comedian Ricky Gervais: "Unbelievable. RIP George Michael."
Actor William Shatner: "Is this year over yet? Too many people are passing away. Rest In Peace, George Michael."