"Brian Wilson was my friend and my brother in songwriting. We shared a similar sensibility, as evidenced by his 4 over 5 chord under 'Aaaah!' in 'Good Vibrations' and mine under 'I'm Into Something Good.' We once discussed who used it first, and in the end we decided it didn't matter. The world will miss Brian, but we are so lucky to have his music." - Carole King, on Facebook
"I know Orbison is the king of emo, but man if there was a human being who made art out of inexpressible sadness ... damn it was Brian Wilson." - Questlove, on Instagram
"The maestro has passed - the man was an open heart with two legs - with an ear that heard the angels. Quite literally. Love and Mercy for you and yours tonight. RIP Brian." - John Cusack, who played Wilson in the 2014 biopic "Love & Mercy," on X
"Rest in Peace!" - Rolling Stones guitarist Keith Richards, on Instagram
"Oh no Brian Wilson and Sly Stone in one week - my world is in mourning. so sad." - Rolling Stones guitarist Ronnie Wood, on X
"Anyone with a musical bone in their body must be grateful for Brian Wilson's genius magical touch !! And greatly saddened of this major worldly loss!! My thoughts go out to his family and friends." - Fleetwood Mac drummer Mick Fleetwood, on X
"First Sly, now Brian ... this is really just ..." - Maggie Rogers wrote on her Instagram Story, adding a heartbreak emoji
"God bless Brian, peace and love to all the family, peace and love Ringo and Barbara." - Ringo Starr, on X
"Anyone who really knows me knows how heart broken I am about Brian Wilson passing. Not many people influenced me as much as he did. I feel very lucky that I was able to meet him and spend some time with him. He was always very kind and generous. He was our American Mozart. A one of a kind genius from another world." - Sean Ono Lennon, on X
"His cherished music will live forever as he travels through the Universe and beyond. God bless you, sweet Brian. One of the biggest thrills of my life was singing "California Girls" with Brian." - Nancy Sinatra, on Instagram
"Brian Wilson was a musical and spiritual giant. His melodies shaped generations, & his soul resonated in every note. I was fortunate to know him; we all were blessed by his genius. Rest peacefully, Brian." - Micky Dolenz of The Monkees, on X
"Sadly, Brian Wilson has passed away. Songwriter, visionary. Thank you for a lifetime of wonderful melodies that spanned decades. I'm going to spend the day listening to the Beach Boys and reminiscing." - Gene Simmons, Kiss co-founder, on X