Legendary US R&B musician Ray Charles has died aged 73 in Los Angeles.
Charles performed 10,000 concerts during a 58-year career
Charles, considered a pioneer of soul music, died of acute liver disease, which was diagnosed after he had hip replacement surgery in December.
Soul diva Aretha Franklin described him as "a fabulous man" who introduced the world to "secular soul singing".
Michael Jackson said he was "a true legend - an American treasure", while Stevie Wonder praised "the genius of his talent of his music".
Charles, who went blind aged six, kept a largely low profile during a recent bout of ill health - but still managed to collaborate with other musicians.
His best-known songs included Georgia on My Mind, Hit the Road Jack and I Can't Stop Loving You.
The 12-time Grammy winner played his 10,000th concert on 23 May 2003 in Los Angeles.
More recently, he had worked on a CD of duets with performers such as Sir Elton John, Norah Jones and Johnny Mathis.
Family members and his manager were present when he died.
"Everybody knows him as the legend, the genius. I just knew him as my father, his loving way, his giving way," said his son, Reverend Robert Robinson.
"He was very straight forward. You knew where you stood. And he always gave great advice, just on life. He would talk to me just about life and what it was to be a man, a true man in this day and time, and that's what I appreciate."
Tributes have been left on the Hollywood Walk of Fame
Manager Joe Adams said Charles had planned to return to performing
"He was not recording. He was still listening to songs. He was still looking for material because he had every intention of coming back," said Mr Adams.
Born Ray Charles Robinson in Albany in the south-eastern state of Georgia on 23 September 1930, Charles went on to become one of America's most enduring musicians.
After the disease glaucoma left him blind as a child, Charles was sent to a school for the deaf and blind in Florida, where he developed a lifelong talent and passion for music.
The young pianist later made his way to the north-western city of Seattle where he first performed as a solo act, modelling himself on the late musical legend Nat "King" Cole.
He was a master of many styles, dabbling in country, jazz, big band and blues.
Battling childhood poverty and adult drug addiction, his intense renditions of classic songs earned him the nickname The Genius.
His last public appearance was alongside Clint Eastwood on 30 April in Los Angeles.
The city has designated the singer's studios, built 40 years ago in the centre of the town, an historic landmark.
Charles died in his Beverly Hills home of complications of liver disease, according to his publicist, Jerry Digney.
"It's devastating," Mr Digney told the AFP news agency. "He's been ailing for while now and it started out with a hip situation and went from there to other things, primarily the liver."
Tributes have also been pouring in from those who knew the man and his music.
"People remember the big hits and the visual image of him, but they forget what an innovator he was in the 1950s as a jazz musician," said country music singer Marty Stuart.
Fellow country music legend, Willie Nelson, said, "I lost one of my friends and I will miss him a lot."
And Hollywood's ceremonial mayor Johnny Grant, who officiates at Walk of Fame ceremonies, said: "The world has lost a true musical genius and I would have to say from what's happening down here on the Walk of Fame, one of the most popular musical person in the world.
"I have never seen news travel so fast and so many people get down to the Walk of Fame as they have today for Ray Charles."