No one's ever disputed the fact that Linda Ronstadt has a rich, full voice. The complaint has always been that she used it so conservatively that her performances were pretty but thrill-less. Saturday night at the Capital Centre. Ronstadt finally took the wraps off her big voice and let loose with some lusty rock 'n' roll.

By the time she got to her new single, "How Do I Make You?", all her coyness was gone. When she kept shouting, "Dream about me!" it was no request from the girl next door but an insistent demand from a woman on the prowl. Ronstadt tested the limits of her velvety throat with an emotionally desperate vibrato.

It was as if Ronstadt has long contained an emotional pool that was finally tapped by new-wave rock 'n' roll's pneumatic drill. Saturday it came gushing out. It came out stronger on the hard core rock 'n' roll numbers: three by Elvis Costello, three by Mark Goldenberg of the Cretones and nine oldies, including a premiere version of the Knickerbockers' 1965 "Lies."

Ronstadt benefited from all-star backing. Keyboardist Bill Payne of Little Feat created the moody textures that framed each song. The three guitars of Dan Dugmore, Danny Korchmar and Kenny Edwards flushed out the beat to a pulsating throb. Peter Asher -- Ronstadt's producer and the Peter of Peter & Gordon -- added vocal and percussions.

A special treat was Wendy Waldman, a vastly underrated singer/songwriter. Waldman, who pushed Ronstadt into a sparkling duet on the Hollies' "I Can't Let Go," sang two of her own songs and brought a harmonic and inflective subtlety that Ronstadt still lacks.

Danny Korchmar led his own quartet through the opening set. In the past, Korchmar has tried his hand at acid-rock, folk-rock, country-rock and jazz-rock. Now he is trying punk-rock. In each case, he executed the superficials perfectly and completely missed the essentials.