By EVELYN RENOLD

Looking like a cheerleader gone punk, Linda Ronstadt closed out six shows at Radio City Music Hall last Tuesday with an enthusiastic, virtuosic performance, touching on her entire post-Stone Poneys recording career.

Her 90-minute set, which blasted off with "Tumblin' Dice" and closed with an emotional rendering of "Desperado," included a surprise appearance by James Taylor, who harmonized with her on "I Think It's Gonna Work Out Fine," from her new album, "Get Closer." Sweet Baby James, in surprisingly animated form, wore modified preppy duds, and provided an amusing contrast to the pony-tailed Ronstadt, who flounced around in a sweater, red boots and pleated miniskirt.

For Ronstadt devotees, the show was inevitably nostalgic - her solo career spans 13 years, and there is an obvious question about how much longer she intends to keep at it. But the performance was reassuring, too: Ronstadt still possesses what is arguably the best female voice in rock and roll. In fact, because of the rigorous training she underwent for her role in "Pirates of Penzance," that voice has more power and range today than it ever did before.

At 36, Ronstadt is naturally looking for new things to do; but if she's bored being a rock star, it sure doesn't show.

From earlier in her career, Ronstadt offered "Silver Threads and Golden Needles," which sounded fresher than ever, and "You're No Good," which allowed for some extended instrumentalizing from her crackerjack band. The members included Andrew Gold, the legendary Waddy Wachtel and Kenny Edwards, who, Ronstadt reminded, produced Karla Bonoff's bright hit, "Personally."

From her last album, "Mad Love," Ronstadt sang Elvis Costello's haunting "Party Girl" and Billy Steinberg's energetically saucy "How Do I Make You?" From the new album, there was "Sometimes You Just Can't Win," previously recorded by George Jones, on which Ronstadt proved, once again, that she can sing straight-ahead country with the best of them. She also performed the title song from "Get Closer," a simplistic rocker which is probably unworthy of her but is rollicking fun anyway.

Other highlights included a cutely choreographed "Poor, Poor Pitiful Me" and a smashing tour de force on "Willin,"' the trucker's anthem. Only Ronstadt's version of Jimmy Webb's bland "The Moon Is a Harsh Mistress" failed to impress.

Ronstadt's stage persona has changed dramatically over the past decade. Some of us can remember a frightened, almost frozen-looking performer at the Palomino Club in Los Angeles some nine years ago, a young woman with a heart-stopping soprano, who careened from one song to the next without ever making contact with her audience. These days, Ronstadt's banter on stage is relaxed and controlled, and she even manages an occasional flash of wit.

That wit, incidentally, was in evidence the other morning on the "Today" show when she stopped a torrent of gushy praise from Bryant Gumbel by asking, "You want to come home with me, Bryant?"

Though Ronstadt has always appealed to men and women, she's still pushing that insouciant sexiness; at Radio City, she punctuated several numbers by vigorously shaking her fanny at the audience.

Ronstadt's basic image continues to be that of the California girl-next-door - a girl who's up for a good time. But the cheerleader outfit - so different from her sophisticated '40s look on the cover of 'Get Closer" - underscored the fact that musically and otherwise, she is still trying on new images. Her next project, in fact, is an album of standards with Nelson Riddle (a similar, previous project with producer Jerry Wexler was scrapped) which she hopes to resume when she winds up the current tour, scheduled for Nov. 29 in Texas.

Wherever her career takes her, this old fan hopes she keeps singing for a long, long time.