Singer Phil Everly, 74

Phil Everly, 74, who with his brother, Don, made up the most revered vocal duo of the rock-music era, their exquisite harmonies profoundly influencing the Beatles, the Beach Boys, the Byrds, and countless younger-generation rock, folk, and country singers, died Friday in Burbank, Calif., of complications from chronic obstructive pulmonary disease, his wife, Patti Everly, told the Los Angeles Times.

"We are absolutely heartbroken," she said, noting that the disease was the result of a lifetime of cigarette smoking. "He fought long and hard."

During the height of their popularity in the late 1950s and early 1960s, the Everly Brothers charted nearly three dozen hits on the Billboard Hot 100 singles chart, among them "Cathy's Clown," "Wake Up Little Susie," "Bye Bye Love," "When Will I Be Loved," and "All I Have to Do Is Dream." The Everly Brothers were among the first 10 performers inducted into the Rock and Roll Hall of Fame when it got off the ground in 1986.

"They had that sibling sound," said Linda Ronstadt, who scored one of the biggest hits of her career in 1975 with her recording of "When Will I Be Loved," which Phil Everly wrote. "The information of your DNA is carried in your voice, and you can get a sound [with family] that you never get with someone who's not blood related to you. And they were both such good singers - they were one of the foundations, one of the cornerstones of the new rock-and-roll sound."

Robert Santelli, executive director of the Grammy Museum in Los Angeles, said Friday: "When you talk about harmony singing in the popular music of the postwar period, the first place you start is the Everly Brothers. . . . You could say they were the vocal link between all the 1950s great doo-wop groups and what would come in the 1960s with the Beach Boys and the Beatles."