Glen Campbell had a string of hits, in the 60's and 70's, with over 70 albums:
(Campbell) "Like a Rhinestone Cowboy."
Dolly Parton says Campbell was special because he was so gifted:
(Parton) "Glen is one of the greatest voices that ever was in the business and he was one the greatest musicians, he was a wonderful session musician."
He made history in 1967 by winning four Grammy's in the Country and Pop categories. The 2014 documentary "I'll Be Me" detailed Glen's farewell tour and struggle with Alzheimer's.
The family is asking for privacy at this time and in lieu of flowers, they say donations can be made to Glen Campbell Memorial Fund at BrightFocus Foundation.
It is with the heaviest of hearts that we announce the passing of Glen Travis Campbell, at the age of 81 https://t.co/zSv4RqjK4H
-- Glen Campbell (@GlenCampbell) August 8, 2017
Thank you @GlenCampbell for the artistry, grace & class you brought to country music. You were a shining light in so many ways.
-- Brad Paisley (@BradPaisley) August 8, 2017
Extremely sad to hear that Glen Campbell has passed away. My prayers and thoughts go out to him and his family.
-- Blake Shelton (@blakeshelton) August 8, 2017
Thank you Glen Campbell for sharing your talent with us for so many years May you rest in peace my friend You will never be forgotten
-- Charlie Daniels (@CharlieDaniels) August 8, 2017
We lost a music legend today. Rest in peace, Glen Campbell. Sending love and prayers to his family. pic.twitter.com/CqW5eMFXAF
-- Rascal Flatts (@rascalflatts) August 8, 2017
-- Grand Ole Opry (@opry) August 8, 2017
Michelle Pollino, FOX News.