NASHVILLE, Tenn. — June Carter Cash's legacy is more than just her duets with husband Johnny Cash. She was a country music pioneer in her own right — singer, musician, composer — as well as an actress and author.

June Carter Cash died Thursday at age 73 of complications from heart surgery. She had been critically ill after surgery May 7 to replace a heart valve.

"People talk about Loretta Lynn and Tammy Wynette when it comes to pioneering women in country music. But they very seldom mention June, somewhat because she got married to Johnny Cash," said Ed Benson, executive director of the Country Music Association.

"I think people should think of her more often when they think of the pioneering women in country music."

The daughter of country music founder Maybelle Carter, June Carter Cash began performing as a child. With her husband, she had such hit duets as "Jackson" and "If I Were a Carpenter," which won Grammy awards in 1967 and 1970, respectively.

In 1999, she released an acoustic album, "Press On," that amounted to a musical autobiography and won her another Grammy.

"There's a lot of people who I love — fans that I've known through the years — who will be glad I did it," she said about the album at the time. "And maybe some other people . . . wonder what Johnny Cash's wife is really like."

Five years before marrying Cash, June Carter Cash co-wrote his 1963 hit "Ring of Fire," which was about falling in love with him.

Longtime friend Kris Kristofferson said Johnny Cash and June Carter Cash have "been partners in life for as long as I've known them — always in love, and always there for each other."

In a 1987 Associated Press interview, June Carter Cash said of her husband: "There's a lot of power to him. I've seen him on shows with people with a No. 1 record or a lot of No. 1 records, but when John walks on that stage, the rest of 'em might as well leave."

In his 1997 autobiography, Johnny Cash described how his wife stuck with him through his years of amphetamine abuse.

"June said she knew me — knew the kernel of me, deep inside, beneath the drugs and deceit and despair and anger and selfishness, and knew my loneliness," he wrote. "She said she could help me. . . . If she found my pills, she flushed them down the toilet. And find them she did; she searched for them, relentlessly."

June Carter Cash was part of country music royalty from the day she was born in 1929.

The Carter Family — her mother, Maybelle; Maybelle's cousin, Sara Carter, and Sara's husband, A.P. Carter — made what are among country music's first recordings just two years earlier. The Carters' harmony singing still inspires artists today and Maybelle's "Carter lick" on the guitar has become one of the most influential techniques in country music.

The family act broke up, but mother and daughters June, Helen and Anita continued on as Mother Maybelle & the Carter Sisters, with little June playing autoharp.

Starting in 1939, the sisters starred in a radio show in Del Rio, Texas, that could be heard as far away as Saskatchewan, Canada. The Carters went on to become staples of the Grand Ole Opry country music show in Nashville.

In the late 1950s, after her marriage to country singer Carl Smith broke up, June Carter moved to New York to study acting at the urging of director Elia Kazan, who had seen her perform while scouting Tennessee for movie locations.

In 1961, she turned down an offer to work on a variety show to tour with Johnny Cash for $500 a week; they married in 1968 after he proposed to her on stage.

In 1979, she wrote an autobiography, "Among My Klediments" (Carter Cash's word for precious mementos) and released "From the Heart," a memoir, in 1987.

Carter Cash did occasional acting roles, including the part of Robert Duvall's mother in the 1997 film "The Apostle." With her husband, she occasionally performed at Billy Graham crusades.

Johnny Cash and June Carter Cash had a son, John Carter Cash, in 1970. She was also the mother of country singer Carlene Carter, whose father was Smith. Singer Rosanne Cash is her stepdaughter.