Williams collapsed on a Las Vegas street after leaving the hospital where he was admitted a week ago for a respiratory illness.

The hospital reported him missing several hours before his body was found.

The singer became famous in 1955 when he recorded Everyday I Have the Blues with Count Basie, and the two worked together for seven years.

Inspired by spirituals

Born Joseph Goreed on 12 December 1918, in Cordele, Georgia, Williams' first musical experiences were playing the piano and singing the spirituals he heard at the Methodist church where his mother was the organist.

In his teens in the 1930s, he led the singing group The Jubilee Boys and later sang solo in a Chicago club, making his professional debut in 1937 with the late Jimmy Noone.

Williams' big break came in 1943, when he was working as a security guard at the city's Regal Theater. There, he was exposed to jazz greats such as Duke Ellington.

After that Williams joined Lionel Hampton's band in Boston and was later hired by Basie.

"Basie said, 'I can't give you what you're worth. But, things get better for me, they get better for you.' I had the good sense to go with him," Williams said of his former partner.

The two played together from 1954 to 1961, and they continued to get together every so often until Basie's death in 1984.

'Messenger boy for God'

Williams continued to sing into his old age at all types of venues; on cruise ships, at festivals, in hotels and clubs.

"I'm most pleasantly surprised at what still comes out of my throat," he said in an 1986 interview.

"I'm thrilled and thankful. I remember Edward (Duke Ellington) saying, 'I'm just a messenger boy for God.' Much of what we do comes through us. I thank God for what comes through me."

Williams' also appeared on TV playing Bill Cosby's father-in-law, Grandpa Al, on The Cosby Show in the 1980s.

Entertainers pay tribute

Friend and singer Buddy Greco said of Williams: "As a talent, he was one of the best blues singers in the world and also one of the best ballad singers.

"There will never be anyone like him, again."

Singer Robert Goulet said: "At the age of 80, Joe could sing better than most people at the age of 20. He was one of the greatest jazz and blues singers of all time, and he was such a good man, too."

The entertainer Tony Bennett said Williams once told him: "It's not that you want to sing, it's that you have to sing."