Correction: An earlier version of the article incorrectly said that Phil Everly wrote the song “Born Yesterday.” It was written by his brother Don Everly. This version has been corrected.

Phil Everly, who died Jan. 3, and his older brother, Don, used their harmonies to capture the sorrows and drama of adolescence for a generation. In doing so, the duo known as the Everly Brothers paved the way for the Beatles, the Byrds, the Hollies, and Simon and Garfunkel.

While it is sometimes argued that much early rock-and-roll — particularly the music of Elvis Presley and Bill Haley — was simply watered-down rhythm and blues, the music of the Everly Brothers stands as a rebuttal to this claim.

The two could — and did — cover songs by Little Richard and Ray Charles with authority, but their roots were in a long tradition of country-music fraternal duos that included the Delmore Brothers, the Louvin Brothers and the Blue Sky Boys. When brothers harmonize, their genetically close voices often produce a distinctive, ethereal sound, and the Everlys exemplified that.

In their case, though, the sound was rendered almost spooky by the fact that Don, the baritone, and Phil, the tenor, hardly ever sang more than a diatonic third apart. Listen to an Everlys song such as “When Will I Be Loved.” Hum Phil’s part, then hum Don’s. Either vocal part can stand alone as a melody. But taken together, the two melodies, rendered by two nearly identical voices, formed what was called a “ghost harmonic” by Graham Nash of the Hollies and Crosby, Stills and Nash.

Phil and Don turned professional before their teens while working with their father, the country guitarist Ike Everly, on the radio in Shenandoah, Iowa. In 1956, they recorded a country record that went nowhere. Their success came a year later, when they applied their old-fashioned “hillbilly” harmonies to pop music with “Bye Bye Love,” the first in a long series of songs written for them by Nashville tunesmiths Felice and Boudleaux Bryant.

The Bryants’ songs chronicled teenage angst without trivializing it. Each song had a specific scenario that teens could relate to. A young couple fears the girl’s parents, who are waiting up for her in “Wake Up Little Susie.” The class clown makes a play for his best friend’s girl in “Bird Dog.” And the slow ballad “All I Have to Do Is Dream” distilled the fantasy and longing behind every high school crush.

The brothers also were prolific songwriters, Phil most notably with “When Will I Be Loved,” later covered in a slick but less soulful fashion by Linda Ronstadt, and Don with “(’Til) I Kissed You.” The latter had the memorable hook of a snare drum imitating a rapid heartbeat.

Perhaps the brothers’ closest kindred spirit was Buddy Holly, the bespectacled Texan with whom they toured in 1957 and ’58. Holly also had sung in a close-harmony hillbilly music duo with Bob Montgomery before he plunged into a rock-and-roll solo career.

The Everlys and Holly shared ideas about songwriting, and Holly pitched several songs to the brothers. Phil served as a pallbearer at Holly’s funeral in 1959. On a BBC show from 1961, Holly’s original rhythm section, the Crickets, appeared as the Everly Brothers’ backup band.

Simon and Garfunkel first recorded in 1957 as Tom and Jerry, in direct imitation of the Everly Brothers, and covered “Bye Bye Love” on their 1970 album, “Bridge Over Troubled Water.”

The Everlys’ influence crossed the Atlantic and can be heard on the Beatles’ first single, “Love Me Do.” Like Phil and Don, Paul McCartney and George Harrison often sang into the same microphone with their instruments pressed forward. Although the Beatles never covered an Everly Brothers number as part of their official studio recordings, they performed a 1960 Everlys song, “So How Come (No One Loves Me),” written by the Bryants, on the BBC. As if proving the extent of their admiration, the Beatles chose a song that was an album track, but not a hit single, for the Everlys.

For nearly four decades, the two brothers knew no life beyond touring together, a fact that only magnified the normal rivalries and resentments of siblings. Phil, the less gregarious of the two, first joined his family onstage at age 5. The brothers endured long periods where they sang together but wouldn’t talk to each other. It all came to a head during a 1973 concert when Phil threw his guitar down and told the stunned audience that they were finished as a group.

In the decade that followed, Phil and Don pursued solo projects. Phil stayed busy as a harmony singer, recording behind Emmylou Harris and J.D. Souther.

However, in 1983, the brothers reunited for a recorded concert at London’s Royal Albert Hall. Perhaps music and time served to heal old wounds. A tour followed, and they recorded two albums, “EB 84” and “Born Yesterday,” for producer and longtime Everlys admirer Dave Edmunds.

Born Yesterday,” the title song written by Don, captured divorce and middle-age disappointment with as much insight as their earlier songs captured adolescence:

He lost his mind today

She threw his clothes away

The love they thought would last

Just flew away

And perhaps to show how things go in circles, the Everly Brothers toured with Simon and Garfunkel in 2003, a reunion for both groups.

“It’s amazing, because they hadn’t seen each other in about three years,” Paul Simon told Rolling Stone. “They met in the parking lot before the first gig.

“They unpacked their guitars — those famous black guitars — and they opened their mouths and started to sing,” he said.

“And after all these years, it was still that sound I fell in love with as a kid. It was still perfect.”