Isaac Hayes, who came into prominence as a hit-making soul singer in the '60s, then went on to compose the film scores for Shaft, Tough Guys , and Truck Turner in the '70s and '80s, then became the voice of Chef on South Park and appeared in several movies including It Could Happen to You and Reindeer Games in the '90s, died Sunday of an apparent heart seizure in Memphis at age 65. Hayes and Bernie Mac, who died on Saturday, performed recently in Soul Men, due to be released in November.