John David “JD” Souther, a member of the Songwriters Hall of Fame known for his collaborations with the Eagles, James Taylor and Linda Ronstadt, passed away peacefully Thursday in his New Mexico home at the age of 78.

The Detroit, Michigan-born Souther, raised in Amarillo, Texas, was known for his longtime partnership with the Eagles’ Glenn Frey, whom he met in Los Angeles after moving there in the late '60s. They formed the band Longbranch Pennywhistle and recorded an album for Jimmy Bowen’s Amos Records. They then went onto collaborate on some of the Eagles’ biggest hits, including “Best of My Love,” “James Dean,” “New Kid in Town” and “Doolin-Dalton.” He also co-wrote “Heartache Tonight” with Frey, Bob Seger, and Don Henley.

Souther was also a successful solo artist, recording his self-titled debut in 1972 before forming The Souther-Hillman-Furay Band with former Byrds member Chris Hillman and Poco’s Richie Furay. A second solo effort, Black Rose, produced by Peter Asher and released in 1976, includes a duet with his one-time girlfriend Linda Ronstadt, “If You Have Crying Eyes.” JD scored his biggest solo hit with “You’re Only Lonely,” from the 1979 album of the same name, peaking at number-seven on the Billboard Hot 100.

Other songs penned by Souther include “Run Like a Thief” for Bonnie Raitt, and several songs for Ronstadt, including “Faithless Love” and “White Rhythm and Blues.” He also recorded several duets with her, among them “Prisoner in Disguise,” “Sometimes You Can’t Win” and “Hearts Against the Wind,” the latter featured in the 1980 film Urban Cowboy. A collaboration with James Taylor, “Her Town Too,” reached number-11 on the Billboard Hot 100.

JD contributed as a singer to artists such as Don Henley, Christopher Cross, Dan Fogelberg and Roy Orbison, among many others. He also appeared as an actor in TV’s Thirtysomething, Nashville and Purgatory as well as the films Postcards from the Edge, My Girl 2 and Deadline.

Souther was declared “a principal architect of the Southern California sound and a major influence on a generation of songwriters,” upon his induction into the Songwriters Hall of Fame in 2013. His final original album, Tenderness, was released in 2015.

He was about to begin a tour with Karla Bonoff on September 24th in Phoenix, through the new year, which will be cancelled.

Souther is survived by his two sisters, his former wife and her daughter, his beloved dogs Layla and Bob, and by countless friends and colleagues within the music community and beyond.

Donations in JD’s honor can be made to Best Friends Animal Society, an organization that was very important to him.