Colombian performer Diomedes Diaz has died at the age of 56. The singer passed away from a heart attack on Sunday (22Dec13) in Valledupar, Colombia, according to the town's mayor, Fredys Soccaras. Diaz was one of the country's best-known performers of local folk music, vallenato. He began his career in 1974 and went on to become one of the nation's best-selling artists of the musical genre. In 2010, he won a Latin Grammy Award for Best Cumbia/Vallenato Album for Listo Pa' la foto. In addition to his music, Diaz was also known for his controversial lifestyle - he struggled with drugs and alcohol throughout his life and in 2002, he was convicted for trying to cover up the overdose death of a fan at his home.