Oscar-winning soul singer and songwriter Isaac Hayes, whose 1971’s “Theme from Shaft” made him the first black composer to win the Academy Award for Best Original Song and earned him two other Grammy Awards, died on Sunday at his home in Memphis, Tennessee, at the age of 65, according to authorities.

Steve Shular, a spokesman for the Shelby County, Tennessee, Sheriff’s Department, said that Isaac Hayes’ wife, Adjowa, his 2-year-old son and a cousin came home from the grocery store and discovered the singer lying unconscious near a running treadmill in a downstairs bedroom, as reported by the Washington Post. He was rushed to the Baptist Memorial Hospital in Memphis, where he was pronounced dead at 14:08 (19:08 GMT).

However, the cause of death was not immediately known.

“Family members believe at this point it is a medical condition that might have led to his death,” a police spokesman declared, quoted by BBC. Furthermore, according to the same source, Mr. Hayes was being treated for several health problems. Moreover, as reported by Reuters, the soul singer also suffered a stroke more than a year ago.

With his profound, smooth baritone and his lustrous, plain dome, Isaac Hayes, hailed as Black Moses, was one of the first black music important figures of the 1970s.

Isaac Lee Hayes Jr. was born on August 20, 1942, in Covington, Tennessee, and, after the death of his mother and the departure of his father, he was brought up by his grandparents.

Mr. Hayes started singing at the early age of five at the local church and taught himself to play the piano, flute, electronic organ and saxophone. He quit school as a ninth-grader in order to work in a restaurant. However, he returned to school and took up music again, becoming the vocalist of a group called the Teen Tones. Moreover, he also joined a gospel group, the Morning Starts, and sang with a rock band known as the Ambassadors.

Isaac Hayes was one of the most significant forces behind music label Stax Records in the mid-1960s. Together with partner David Porter, he produced and wrote numerous songs for several artists, including Sam and Dave’s “Soul man,” which shortly became a gold record.

Nevertheless, Isaac Hayes did not give up his initial dream to be a singer and, in the late 1960s, the renowned songwriter also became a recording artist and released very successful soul albums such as “Hot Buttered Soul” in 1969 and “Black Moses” two years later.

In the 1980s, the now well-known soul singer took up acting. He played in various productions including 1988’s “I’m Gonna Git You Sucka”, 1994’s “It Could Happen to You” with Nicolas Cage and “Reindeer Games”, nine years later, with Ben Affeck.

More than a decade ago, Isaac Hayes became popular among the modern generation as he started playing the voice of Jerome “Chef” McElroy, the school cook on the animated TV hit “South Park.”

Mr. Hayes was inducted into the Rock and Roll Hall of Fame in 2002 and the Songwriters Hall of Fame four years later. He was married four times and was the father of 12 children.