Country music singer Don Williams, one of the biggest stars of the 1970s and 1980s, died on Friday at the age of 78, his publicist said.

Williams, known as "the Gentle Giant" because of his 6-foot, 1-inch frame, mellow voice and low-key profile, had hits with "Tulsa Time," "I Believe in You" and "It Must Be Love," over the course of a 50-year career.

He died on the same day as Troy Gentry, one half of the country music duo Montgomery Gentry, who was killed in a helicopter crash in New Jersey.