NEW YORK — Jean Shepard, a mainstay of the Grand Ole Opry whose feisty honky-tonk songs of the 1950s and ’60s paved the way for the brash, assertive style of such singers as Loretta Lynn, died Sunday in Gallatin, Tenn. She was 82.

She had Parkinson’s and heart disease, her husband, Benny Birchfield, said.

Ms. Shepard, who grew up on the country blues of Jimmie Rodgers and the Western swing of Bob Wills and His Texas Playboys, brought a freewheeling, cheeky style to the eternal themes of heartache and cheating, planting the flag for independent women.

“Stand by your man’’ became “call out your man’’ in such songs as “The Root of All Evil (Is a Man)’’ and “Many Happy Hangovers to You.’’ She suggested she might be ready for a little adventure herself in “Twice the Lovin’ in Half the Time’’ and dared speak up for women on the wrong side of love in “The Other Woman.’’

In 1963, her first husband, singer Hawkshaw Hawkins, died in the plane crash that killed Patsy Cline.

Ms. Shepard was small — “she’d have to stand on a stepladder to pick corn,’’ one TV host said by way of introduction — but her voice was powerful, pure, and penetrating, not unlike Webb Pierce’s weapons-grade tenor. She was also an expert yodeler, a skill she showed off in her 1964 hit “Second Fiddle (to an Old Guitar).’’

In 1955, she became the third woman to join the Grand Ole Opry, after Minnie Pearl and Kitty Wells, and performed there for six decades. Her biographical entry on the Opry website notes that “there was really no precedent in country music for a young woman recording and touring on her own rather than as a member of a family team, couple, or as a band’s ‘girl singer.’’’

Her success as a solo act changed the landscape of country music, opening the door for artists such as Lynn, Cline, and Tammy Wynette.

It was a hard-won victory. At the start of her career, she met Hank Williams and told him she wanted to be a country star.

“He said: ‘Oh yeah? Well, there ain’t much room in this business for a woman country singer,’’’ she recalled in an interview with The Guardian in 2012. “That was the general attitude back then, but it only made me more determined. Weren’t nothing going to stop me doing what I wanted to do, which was singing traditional country music the way it’s supposed to be sung.’’