Of all the music-related memoirs due this fall (the release date is Tuesday), Vivian Cash’s is liable to be the most surprising. With abundant evidence to make her case, Vivian Cash, the first wife of Johnny Cash, explains how her role in his life was expunged by the mythology that sprung up around him. Her book, put together with the help of Ann Sharpsteen, vehemently corrects the impression created by “people of the Nashville mind-set, who prefer that I be written out of Johnny’s history altogether..”

Most of this unusual book was actually written by Johnny Cash. After a brief introduction it becomes a string of the near-daily letters he wrote to his sweetheart, Vivian Liberto of San Antonio, during the three years he spent in the Air Force. They met at a skating rink in July 1951, when Vivian was a petite, exotically beautiful 17-year-old schoolgirl. Soon Johnny, then a 19-year-old serviceman, was on his way to Germany. He did not see Vivian again until the summer of 1954.

Vivian Cash died in 2005, after spending much of her life avoiding revisionist versions of Johnny Cash’s life story. With any luck she never saw “Walk the Line,” the 2005 hit movie that presented her as a nagging, ever-pregnant obstacle to his storybook romance with June Carter, who became his musical partner and second wife. The film’s Vivian could not be less like the one described by Cash in love letters presented here.

This book does not include Vivian’s side of the correspondence. Nor does it need to: Johnny’s impassioned dialogue is conducted as much with himself as it is with her. Desperate to idealize his little angel as sweet, clean, pure and holy, he is equally desperate to hang onto her despite the strain of long separation. The letters become both fascinating and agonizing as Johnny Cash creates and then overburdens the wild romantic fantasy that sustains him through lonely years.

At first he swoons over the memory of ruining Vivian’s lipstick and bobby pins. He promises her “oceans and oceans of love and devotion.” And even at this early, innocent stage he tells her everything, no holds barred.

“Honey, I’m the only guy I know that tells his girl about the girls he runs around with over here,” he writes. “I’ve told you everything, and I’m glad we understand each other.” At the same time he expresses a loathing of his buddies’ flagrant sinfulness and promises never to be heedless of what he does. “Baby, I’d trade 100 of girls like that for one kiss from you.”

Pouring out a correspondence so torrential that he says it scares the mail clerk, Cash returns constantly to his greatest fears: drinking and disloyalty. His first lapse into drunkenness is treated as a terrible accident. “I promised my mother I’d never drink,” he confesses. “Believe me, I’m ashamed.” But promises to avoid alcohol are broken over and over.

He complains convincingly he loves her so much it hurts. He repeatedly promises to be forever devoted, no matter what. (”Your little body might be all out of shape from carrying so many of my kids, but that will just make me love you more.”)

He creates a fantasy world as tantalizing as it is unattainable. The correspondence stops when he returns home to marry Vivian and begins tearing their dream world apart.

Quicker than you can say “show business success story,” Johnny’s priorities change. Vivian becomes the mother of four daughters, and he becomes the man skyrocketing to the top. The little Southern family is transported to California, home base for that behavior that Johnny once feared. Vivian blames some of his violent transformation on substance abuse and much of it on Carter, who supposedly once declared: “Vivian, he will be mine.” And then he was. “Let me tell you, it was horrible to be on the receiving end of her determination,” Vivian Cash writes.

“I Walked the Line” is a wildly romantic book, but also a sad and wrenching one, a testament to the destructive power of hopes pushed past the breaking point. Although her narrative sounds almost willfully naive, that makes her book more revealing.

Vivian has what she says is a big secret: that she never stopped loving Johnny, not even after each of them remarried. In his final months, then an ailing widower, he spent enough time with Vivian to authorize publication of his letters.

Cash’s admirers remember him well in that last, painful part of his life. Now they can also picture him as a just-grown man with a very different idea of what it meant to be in pain.

–Janet Maslin, The New York Times