There was a time back in 1974 when singer Barbara Mandrell joined some other Nashville purists who spoke out passionately against the invasion into country music of pop superstars like Olivia Newton-John and John Denver. Now, almost seven years later, not only is Mandrell proving she harbors no lingering resentment for the commercialization of country, but she also turns out to be rather adaptable herself. She spent most of the last half year in a $2.8 million manse on the residential extension of Rodeo Drive and is bombing around Beverly Hills in one of her two Rolls-Royces. Given a recent boost by the success of Urban Cowboy, the once feuding world of country artists seems like one big, happy, outrageously wealthy family of Beverly Hillbillies.

What brought Mandrell to town at 31 was the chance to headline her own six-week variety series on NBC—which the network extended after New Year's to 13 weeks. Her guests have included mighty country-popsters like Kenny Rogers—whom Barbara upset last October for the Country Music Association's Entertainer of the Year Award—and Dolly Parton. "It makes no sense time-wise or money-wise for me to do the show," admits Nine-to-Fiver Parton, "but I love Barbara and wanted to help any way I can."

The show was never exactly helpless, woman-wise. Its full title is Barbara Mandrell and the Mandrell Sisters, referring to her stunning younger siblings Louise, 26, and Irlene, 24. They sing backup and join in the skits, which are a sort of cross between Hee Haw and Smothers Sisters. The dominant force is Barbara, who plays banjo, piano, steel guitar and saxophone as well as warbling her greatest hits, like Sleeping Single in a Double Bed, (If Loving You Is Wrong) I Don't Want to Be Right, You Can Eat Crackers in My Bed and the latest, The Best of Strangers.

A prime-time series is probably the diciest gamble a singer can take—Parton herself failed with a syndicated show. But, asked if she's worried about flopping, Mandrell responds, "I'm not made up to even consider that. I just want to go for it all." Her second-billed sisters also deemed television a propitious move. Irlene, a Nashville model who dreams of becoming a Goldie Hawn-style comedienne, says: "I had no hesitation. I had everything to gain." Louise—the tallest, darkest and sexiest Mandrell—wants to be a singer, though her first two albums died on the charts. "If I ever get jealous," she notes, "I remind myself that Barbara is five years older than me—which means I have some time to catch up."

The Mandrells have always been tight-knit and in the late 1960s toured together as a family band. The matriarch, Mary, a former music teacher who played electric bass with the band, held the fort in Nashville this fall while the girls were taping in L.A. but has since gone West to join her husband, Irby, Barbara's manager. Barbara's business administrator, husband Ken Dudney, 39, and their children Matthew, 10, and Jaime, 4, live in the opulent Rodeo Drive home, which, she hastily points out, was rented and provided by her producers. "It just amuses me when people put on the dog," says Barbara, though she's obviously learned to play the game. For example, she had her Chevy Surburban truck driven out for her stay. "We found out if you want to get stared at in Beverly Hills, you drive a truck," Barbara observes. "Nobody notices you in a Rolls."

For all her Tennessee chauvinism and determination to live there, Barbara spent her early days in Oceanside, Calif., singing in a madrigal choir during high school. By the age of 11, she was playing pedal steel in Red Foley's show in Las Vegas. Then the Mandrells put together their family band, recruiting Ken Dudney as drummer, and Barbara married him in 1967.

Louise dropped out as bass player in 1971 to work as an engraver in Texas and a waitress in Nashville before launching a solo career of her own after her second divorce, in 1977. She is now wed to Nashville singer-songwriter R.C. Bannon. Irlene's present and only husband, Rick Boyer, plays bass for Eddie Rabbit. (Both of the younger Mandrells say that they are postponing having children until their careers are further along.)

Barbara's home base is a $250,000 brick retreat on five acres fronting Old Hickory Lake, 25 miles outside Nashville. Louise has a place next door, and Irlene closer to town. Barbara and Ken also own an Aspen condo, where they make a point of getting away sans kids two weeks a year. A devout Christian, Barbara tries to get to church on Sunday and calls her backup band the Do-Rites—appropriately. Anyone caught boozing or doping on her bus is fired.

Perhaps the greatest sign of Mandrell's rising status occurred last May, when she became the first C&W songstress asked to perform at the Swan Ball, Nashville's snootiest society event of the year. "She didn't grow up so poor, like Loretta Lynn and the others," explained one of the organizers. Barbara's success has led to some tension at home. "In the past I've had feelings of inadequacy," admits husband Ken, who recently gave up his job piloting a jet for the Tennessee governor to devote himself full-time to Barbara's work. "But she's been wise and helped me over the troubled times," he says, "and I contribute by taking care of most of the financial affairs." Besides, he adds, "We haven't been together this much in a long time."

Barbara makes no apologies for her ambition, however, and for her up to 250 days a year on the road. "I am driven," she declares, "and I never see myself being a has-been. The reason is that I'm competing against the toughest competitor there is—me."