Linda Ronstadt's evolution as a sophisticated pop stylist has proceeded at the sort of pace, and, more recently, with the kind of high-gloss aesthetic that rankles rock critics. Instead of bold shifts in style, she has always approached any revisions slowly and with great care. While that yields moments when her formidable technical powers overshadow the material at hand, it also yields some of her best performances.

Like its predecessor, "Simple Dreams," "Living in the U.S.A." adheres to the unadorned ensemble approach gradually arrived at over the course of Ronstadt's previous collaborations with producer Peter Asher. The current band is the same one unveiled on that last album, and the partnership sounds further seasoned, distinguished from earlier bands by the spectrum covered between Waddy Wachtel's razor-sharp electric guitar and Don Grolnick's more rhapsodic, jazz-tinged piano. This group seldom turns in the sort of back-lit, high relief instrumental effects that Andrew Gold's did on Ronstadt's mid-'70s LPs; instead, the approach is subtle, never overpowering the singer.

More central to the LP's character is Ronstadt's continued development as a singer. Whether or not you find her impassioned attack thrilling or merely hyperbolic, there is little doubt that she has gained further control over her instrument, displaying greater depth as well as more sheer, visceral power. In particular, her ease with flat-out rock & roll phrasing shows she is no longer afraid to step beyond the conventional prettiness of her full-throated ballad style. She roughs things up more convincingly now, spitting out lyrics or biting them off in taut syncopations. That flexibility also leads to a subtler victory on what might have been one of the set's more obvious choices, Eric Kaz's Blowing Away: Instead of the plaintive romanticism we might have expected, Ronstadt sings the title chorus without vibrato, accentuating the song's ennui.

While she again draws from familiar Los Angeles peers (J. D. Souther, Little Feat, Warren Zevon) and rock & roll masters (Elvis Presley and Chuck Berry), there are also some offbeat wrinkles. On the Hammerstein/Romburg chestnut When I Grow Too Old to Dream, her reading is beautifully restrained, shaded by Mike Mainieri's spare vibes setting. Better still is Ooh Baby Baby, whose classic Smokey Robinson performance no doubt challenged Ronstadt to provide her most persuasive soul styling yet.