One half of the influential brothers whose harmonies left their mark on the Beatles, the Byrds and many others
Everly's high, close-harmony singing with his older brother, Don, made the Everly Brothers one of the biggest rock and country acts of the 1950s and early 1960s.
Everly died in the Los Angeles suburb of Burbank of complications from chronic obstructive pulmonary disease, his wife Patti told the Times.
"We are absolutely heartbroken," Patti Everly told the paper. "He fought long and hard."
Representatives for Phil Everly could not immediately be reached for comment.
The Everly Brothers profoundly influenced 1960s-era artists ranging from Beatles John Lennon and Paul McCartney, who early in their careers called themselves the Foreverly Brothers, to Simon and Garfunkel, the Byrds, the Hollies and the Beach Boys.
"Perhaps even more powerfully than Elvis Presley, the Everly Brothers melded country with the emerging sound of 50s rock & roll," Rolling Stone magazine said in placing the duo at No 33 on its list of the 100 greatest artists."
Phil and Don had an onstage breakup in 1973 that led to a decade-long estrangement, but Phil later told Time magazine their relationship had endured.
"Don and I are infamous for our split," Phil said, "but we're closer than most brothers. Harmony singing requires that you enlarge yourself, not use any kind of suppression. Harmony is the ultimate love."
Phillip Everly was born on 19 January 1939, in Chicago, the son of two country musicians, Ike and Margaret Everly.
With Ike Everly on guitar, the family was a traveling act and had a radio show in which Phil and Don performed between commercials for XIP rat poison and Foster's 30-minute Wonder Corn and Callus Remover. The legendary Nashville guitarist Chet Atkins was one of their earliest supporters.
"One thing that impressed me when I met those kids was that they were so intelligent," Atkins said on the Everly family fan site. "Don and Phil used proper English and I just thought they were a cut above ... intellectually and education-wise."
Their breakthrough hit, Bye Bye Love, came in 1957 and rose to No 2 on the US charts. It was their first million-seller and the first of numerous Everly tunes written by Boudleaux Bryant and his wife Felice, including, All I Have to Do Is Dream, Wake Up Little Susie and Devoted to You.
Wake Up Little Susie, also released in 1957, was their first No 1 hit. A song about two teenagers falling asleep at the drive-in and waking up long after curfew, it was banned in Boston for its ever-so-slightly suggestive lyrics.
In 1960 the brothers signed with a new record label, Warner Brothers, agreeing to a 10-year, $1 million contract and making their debut with their own song, Cathy's Clown, but by then their career was in decline.
The Beatles may have led to the clean-cut brothers' undoing in the tumultuous 1960s, but they were on a downward path at least a year before the Fab Four exploded on the scene, according to the Country Music Hall of Fame, which inducted the Everlys in 2001.
"They broke with [record producer] Wesley Rose in 1961, moved to California, and began making singles that were probably too experimental for the time," it said, also citing a slowdown in touring and a loss of access to the Bryants' songs due to a split with the music publishing firm Acuff-Rose.
But the songs lived on through some of the biggest acts of the era, including Simon and Garfunkel, who recorded Bye Bye Love on their 1970 hit album, Bridge over Troubled Water.
Art Garfunkel told Rolling Stone that the brothers' harmonising had taught him that "every syllable can shine".
"They were Kentucky guys with beautiful, perfect-pitch harmonies and great diction. All those vowels and consonants, those s's and t's, every one of them killed me," he said.
In 1973, with both suffering health and stress problems from years of touring, the Everlys broke up during a concert at Knott's Berry Farm amusement park in Buena Park, California.
"Phil Everly threw his guitar down and stormed off the stage during a performance of Cathy's Clown, leaving Don to tell the stunned audience the group was finished," Rolling Stone said.
In September 1983, after a decade of solo projects, they reunited for a show at London's Royal Albert Hall.
The brothers drew critical acclaim, and the concert yielded an album and a DVD.
The Everlys released EB 84 in 1984 to more acclaim and scored a minor hit with the album's On the Wings of a Nightingale, written for them by Paul McCartney.