She had already outgrown her first band, the Stone Poneys, and in the next years flitted from one persona to the next — country singer, folk hippie, soft-rock crooner — diligently refining her voice, with its huge dynamics and complex tonalities. So subtle an instrument did it become that the audio innovator George Massenburg would sometimes ask Ms. Ronstadt to sing a few notes, which he then used to evaluate the latest magnetic tapes. But for Ms. Ronstadt it all began with the song, with “the narrative,” and the search for fresh material that would break through the clichés of lost love. In the memoir, she recalls sharing a cab with the singer-songwriter Jerry Jeff Walker after a night of music in Greenwich Village. Mr. Walker, his face “scarcely visible,” sang the first verse of “Heart Like a Wheel,” a ballad he’d heard the Canadian sisters Kate and Anna McGarrigle sing at a folk festival. The lyric began with raw emotions but seasoned them with metaphor — the wheel that when it bends can’t be mended — and a plaintive question, “What I can’t understand/Oh please God hold my hand/ Why it had to happen to me?”

Here was a story that could be sung but also interpreted. “I felt like a bomb had exploded in my head,” Ms. Ronstadt writes.

Other songwriters were emerging too — Karla Bonoff, Jackson Browne, J. D. Souther, Warren Zevon — many of them living in Southern California. Gram Parsons, a prodigy from the Deep South by way of Harvard, was on the scene as well. A new country-inflected sound, sentimental but sophisticated, was taking shape, its refined instrumentation honed in clubs like the Ash Grove and the Troubadour and then burnished in the studio.

Ms. Ronstadt was its muse and signature performer, especially after the drummer Russ Kunkel taught her how to sing behind the beat. But even as Ms. Ronstadt and her posse were extending the innovations of the Beatles and the Rolling Stones in the studio, figures like Mr. Dylan and Mr. Young mounted a counter-revolt, stripping down their effects. A new epithet, “overproduced,” entered the debate and then dominated it, with the advent of punk. Ms. Ronstadt made no apologies. “I loved high-fidelity sound,” she said. “I chased it all my life.” And followed it wherever it led — to Broadway (“The Pirates of Penzance”), to the American standards she revisited with Nelson Riddle, to the keening Appalachian harmonies on her “Trio” recordings with Ms. Harris and Dolly Parton, to the Mexican songs that carried her back to her Sonoran roots.

Most of those records sold well and brought Ms. Ronstadt fresh accolades (and Grammys), but they also implied she had eased into the upholstered wastes of “adult contemporary.” Even hits she recorded with Aaron Neville seemed studies in mellifluousness, without sharp edges. She seemed in self-exile from the action.

Her memoir is a reminder of how close to the epicenter she once had been. She opened for the Doors (and was unimpressed with Jim Morrison) and toured with Mr. Young, whom she reveres. A highlight of the book is her account of an all-night jam with Mr. Parsons and Mr. Richards, Mr. Parsons disappearing at intervals to ingest more drugs. At one point, Mr. Richards played “Wild Horses,” a new song he had written with Mick Jagger for the next Stones album. Mr. Parsons begged to record it ahead of them. To her astonishment, Mr. Richards complied.