Don Everly, half of one of the most popular and influential duos in rock history, died on Saturday at age 84. A representative confirmed Everly's death, of a cause not immediately known, to the Los Angeles Times.

Everly was preceded in death, in 2014, by his brother Phil — the other half of the Everly Brothers. Melding keen vocal harmonies with bright melodies and toe-tapping rhythms in an era when the boundaries between rock and country were still being drawn, the Everly Brothers became one of the most beloved groups of the late 1950s and early '60s, with hits including "All I Have to Do is Dream," "Wake Up Little Susie," and "Bye Bye Love." Influences on artists including the Beatles, the Beach Boys, and Simon and Garfunkel, the Everly Brothers were part of the inaugural class welcomed by the Rock and Roll Hall of Fame in 1986.

Discovered in Nashville by family friend Chet Atkins, both Everly Brothers were guitarists. While many of their hits were written by songwriters like Felice and Boudleaux Bryant, Don Everly wrote some of the duo's own most memorable songs — including "Cathy's Clown" (1960) and "(Till) I Kissed You" (1959). It was also Don who played the earworm rhythm guitar intro to "Wake Up Little Susie," which earned him the first-ever Iconic Riff Award from the Musicians Hall of Fame and Museum.

After their last top ten hit in 1962 ("That's Old Fashioned (That's The Way Love Should Be)"), the Everlys saw their commercial fortunes decline. They ultimately split up for most of the 1970s, reuniting to enjoy a second career phase as collaborators (both individually and as a duo) and live concert draws. Paul Simon welcomed his musical heroes into the studio (they sang backup on the title track of Simon's classic Graceland) and onto the stage, where they toured with an also-reunited Simon and Garfunkel in the early 2000s.

Despite the brothers' extended rifts, Don greatly mourned Phil and paid daily respects to his younger brother's cremated remains. As Don said in 1999 (according to Rolling Stone), "Everything is different about us, except when we sing together."

"Many today forget how crucial the Everly Brothers' songs and sound was to early rock and roll," tweeted music journalist Ann Powers. "Their blend influenced so many and captured the hungry, addled teenage heart like little else."