John David “JD” Souther, a prolific songwriter and musician who helped shape the country-rock sound that took root in Southern California in the 1970s with his collaborations with the Eagles and Linda Ronstadt,

JD Souther, the singer, songwriter and actor who co-wrote some of the biggest hits of the Eagles, like “New Kid in Town” and “Best of My Love,” and had a long solo career that included the top 10 hit “You’re Only Lonely,

John David “J.D.” Souther, known for co-penning hits with the Eagles, James Taylor, and Linda Ronstadt, has died at the age of 78.