June Carter Cash, a singer, songwriter and actress and the wife and collaborator of Johnny Cash, died yesterday in Nashville. She was 73.

She had been critically ill since having surgery at Baptist Hospital on May 7 to replace a heart valve.

Of all her accomplishments, the best known is probably the hit song "Ring of Fire," which is about falling in love with Johnny Cash, and which he performed. Ms. Cash wrote the song with Merle Kilgore in 1963, long before her marriage to Mr. Cash in 1968 but after she had become close to him, working with him on cross-country tours. Instead of the usual seraphic love language of teen-angels, it used images of suffering and hellfire and is probably the most complicated popular love song in country music.

Valerie June Carter Cash was born into the Carter Family, the most important of the early country music groups, and one that helped changed it from a string-based music to a vocal music. Her mother was Mother Maybelle Carter, who sang and played guitar on songs like "Single Girl, Married Girl" and "I'm Thinking Tonight of My Blue Eyes," some of the most important recordings of early commercial country music in the late 1920's.

She first lived in Maces Spring, Va., the hometown of her father, Ezra Carter, a farmer. But when she was 10 the family moved to Texas to be near the high-watt radio station XERA in Del Rio, Tex., where they performed on regular radio shows.

By the late 1930's she was performing with the group on records, radio shows and stages. At its largest, the group included Ms. Cash, her sisters Helen and Anita, her cousin Janette, her mother, and her mother's cousins Sara and A. P. Carter. June Carter had her own feature numbers, like "Engine 143," which she sang in a wobbly but vigorously open-throated girl's voice, accompanying herself on autoharp.

The original Carter Family group dissolved in 1943. Ms. Cash, her sisters and her mother began touring and recording as Mother Maybelle and the Carter Sisters. June was the most outgoing of the group, a comedian as well as singer, and the shows mixed traditional songs of the Carter Family (like "Will the Circle Be Unbroken") with pop, gospel and vaudeville comedy. June created a routine involving a deep-country character named Aunt Polly.

By 1946 the group had developed a substantial audience through regular appearances on the "Old Dominion Barn Dance" program broadcast over WNOX in Knoxville. She crossed over to the pop charts with a hit song, "Baby It's Cold Outside," recorded in 1949 with the comedy duo Homer and Jethro.

By 1950 Mother Maybelle and the Carter Sisters were regulars at Nashville's Grand Ole Opry. It was there that Ms. Cash met Elvis Presley, as well as two of her future husbands, the singer Carl Smith, and then Mr. Cash.

In her brief union with Mr. Smith she had a daughter, Carlene. She is also survived by her son with Johnny Cash, John Carter Cash; her daughter with her second husband Rip Nix, Rozanna Cash; her stepchildren Rosanne, Tara, Kathy and Cindy; and several grandchildren.

In 1955 and 1956, the director Elia Kazan saw her perform and encouraged her to try stage acting. Newly separated, Ms. Cash took the advice, studying with Lee Strasberg and with Sanford Meisner at the Neighborhood Playhouse in New York and staying with the Kazan family; on weekends she flew home to Nashville with her young daughters to perform at the Opry.

In the mid-50's she was managed by Colonel Tom Parker and toured with Elvis Presley. It was Presley who first told her about Johnny Cash, intriguing her with his description of how he managed to command an audience onstage while staying perfectly still. She and Mr. Cash finally met in 1956 backstage at the Grand Ole Opry, and she has written of an instant mutual fascination.

In liner notes for Mr. Cash's "Love, God, Murder," she described his eyes. "Those black eyes that shone like agates," she wrote. "I only glanced into them because I believed that I would be drawn into his soul and I would never have been able to walk away." In "I Still Miss Someone," from 1958, he sang, "I never got over those blue eyes/I see them everywhere."

By 1961, June Carter was married to her second husband, Mr. Nix, and Maybelle and the Carter Sisters (renamed the Carter Family after the death of the original family's patriarch, A. P. Carter, in 1960) became part of Johnny Cash's touring show. She stuck to an old-fashioned, wholesome image, while Mr. Cash was becoming famous for drug taking, onstage swearing and explosions of temper. It was the worst period of Mr. Cash's addiction to barbiturates and amphetamines.

Ms. Cash was one of his closest confidantes, and she began hiding and throwing away his pills. She finally helped him to find counseling, and Mr. Cash often credited her thereafter with saving his life.

In 1967 they made an album together, "Carryin' On," including the duet "Jackson," which won a Grammy. (They won another Grammy for their duet "If I Were a Carpenter" in 1970.) Soon after, they became engaged.

Once married to Mr. Cash, she became a fixture in his show, telling jokes and singing, often appearing in antique lace dresses amid the silk and sequins and tasseled suits that were the standard outfits for country stars well into the 1970's. In the 1970's she also acted, and took roles on "Gunsmoke" and "Little House on the Prairie," among other programs. She wrote a memoir, "Among My Klediments," in 1979, and a book of autobiographical vignettes, "From the Heart," in 1987.

She acted little after her marriage to Mr. Cash, but appeared in Robert Duvall's film "The Apostle" in 1997, playing the mother of Mr. Duvall's character. In 1999 she released her second solo album, "Press On," a rough, unostentatious, charming record, which won a Grammy. It included songs from the Carter Family repertory as well as a new arrangement of "Ring of Fire" and several of her own songs, like "Tiffany Anastasia Lowe," a song admonishing her granddaughter of the dangers of Hollywood life.

She and Mr. Cash divided their time between a house at the base of the Clinch Mountains in Virginia and estates in Nashville and Jamaica. Mr. Cash was seriously ill recently with diabetes and pneumonia.

June C Cash