Sonny grew up in Wichita Falls, Texas, After college, he moved to San Francisco and played rock & roll in area clubs. At the urging of guitarist and publisher Pete Drake, he switched to country music and moved to Nashville in 1964. In 1965, Bobby Lewis had a Top Five hit with Throckmorton’s “How Long Has It Been.” In 1975, Throckmorton moved back to Texas because he had promised himself that he would quit music if he didn’t succeed by age 35. Success was just around the corner, and in nine months, over 150 of his songs were recorded, including “Thinking of a Rendezvous,” Johnny Duncan’s first number one hit. Another of his songs, “Knee Deep in Love with You,” became a country standard. Between 1976 and 1980, a Throckmorton song appeared on the charts almost every week. His 1978 hit for Jerry Lee Lewis, “Middle Age Crazy,” even became the basis of a major movie by the same name, and he was named Songwriter of the Year by the Nashville Songwriters Association three years in a row between 1978 and 1980.
Throckmorton’s stature as a major songwriter flourished and in 1980, he was named BMI Songwriter of the Year. Seven years later, with innumerable hits under his belt, he was inducted into the Nashville Songwriters Hall of Fame. He retired to his Texas farm to be with his family.