US bluegrass legend Ralph Stanley dies at 89

American bluegrass pioneer Ralph Stanley has died at the age of 89, according to his grandson, who said the singer and banjo player had been battling skin cancer.

Part of the first generation of bluegrass musicians, Stanley came to mainstream attention through the 2000 Coen brothers movie "O Brother, Where Art Thou?," for which he provided a Grammy Award-winning a cappella rendition of traditional folk song "O Death."

"He went peacefully in his sleep due to a long, horrible battle with skin cancer," musician Nathan Stanley announced on his website on Thursday. 

Stanley was born and raised in southwest Virginia, where he and his brother Carter were taught clawhammer style banjo by their mother, according to a biography released by his publicist Kurt Webster.

The Stanley Brothers popularized "Man of Constant Sorrow," which was later recorded by Bob Dylan, and toured the country playing folk and bluegrass festivals during the 1960s. 

Ralph continued to tour after his brother's death in 1966, drawing from his Appalachian roots to adopt the a cappella singing style of the Baptist church choir from home. 

He teamed up with Ray Cline, Larry Sparks and Melvin Goins to reform an early band, the Clinch Mountain Boys, and went on to record an early Stanley Brothers song with Dylan in 1997.

He performed at the inaugurations of presidents Jimmy Carter and Bill Clinton, and was awarded a "Living Legends" medal from the Library of Congress and a National Medal of Arts presented by George W. Bush. 

He was 73 when he was introduced to a new generation of fans through the soundtrack to "O Brother, Where Art Thou?," which became a runaway hit, topping the Billboard 200 chart. 

Despite health problems, he continued to record and tour into his 80s, often performing with his son Ralph Stanley II on guitar and his grandson Nathan on mandolin.

He is survived by his wife Jimmie Stanley, three children, seven grandchildren and a great grandchild.