In 1968, Vivian Perlis, a research librarian at Yale, knew that she needed to talk to Julian Myrick. A man who had spent his life in the insurance business was not the most likely of musicological sources. But Myrick’s business partner had not only been significant in the field of life insurance, but was also one of the most important figures in American music history: the composer Charles Ives, who had died 14 years earlier.

“He was writing music at the time when I first knew him,” Myrick recalled to Perlis, in a Southern drawl. “He worked very hard at it, but people couldn’t understand it.”

Myrick was only the beginning of what became Perlis’s landmark resource, celebrating its 50th anniversary this season: Yale University’s Oral History of American Music. Over the following years, Perlis sought out more of Ives’s friends and acquaintances. “I searched for the oldest and most fragile Ives survivors and often found myself in hospitals and rest homes waiting for an aged Yale classmate or Ives relative to wake from a nap to tell his story,” she would later recall.

She even tracked down the barber who cut Ives’s hair: a man nicknamed Babe, who hadn’t known that his patron was a composer but did remember that Ives once yelled at him to shut off the radio. Perlis assembled these and other recollections into a groundbreaking 1974 book, “Charles Ives Remembered: An Oral History.”