MUSIC REVIEW : Von Stade Exudes Dauntless Charm : The beloved mezzo-soprano encounters some technical problems in an Ambassador recital but compensates with style and finesse.

Frederica von Stade, who offered a characteristically sophisticated and discerning recital of songs and arias Wednesday night at Ambassador Auditorium, could charm a turtle out of its shell.

For 20 odd years she has captivated the world with a silvery voice more notable for suavity than weight. But she is hardly your everyday garden-variety mezzo-soprano. She is one of those rare songbirds who happens to come equipped with brains as well as vocal cords.

She has taste. She has flair. She has style. She has looks. She has wit.

Sometimes, of course, she also has problems.

On this occasion, she seemed to be suffering some sort of vocal indisposition. Perhaps it was just an off night. Even paragons are entitled to them.

Her intentions were exemplary, as always. The execution of those intentions, however, sometimes precluded a meeting with her own loftiest standards.

On a good day, Von Stade commands a seamless line throughout her considerable range. Wednesday, one couldn’t overlook certain register breaks.

On a good day, her singing is effortless, her tone vibrant. On this day, her singing sometimes sounded labored, her tone breathy and thin.

On a good day, she takes accuracy for granted. This time, she had to approximate certain effects, and she even encountered recurring pitch problems.

Did it matter? Not much.

Von Stade singing a little flat is still vastly preferable to most dutiful divas singing exquisitely in tune. She is, after all, an artist who allows the listener to sit back, relax, and take interpretive illumination for granted.

Refinement, too.

For warm-up exercises, she made a couple of brave gestures in the daunting direction of Handel. “Ombra mai fu” from “Serse” found her passionate in pointing the recitative, somewhat challenged in tracing the endless legato contours. In the florid convolutions of “Dopo notte” from “Ariodante,” she benefited from heroic bravado if not from perfect aim.

Four Lieder of Richard Strauss, which came next, allowed her to slip into introspection mode, and her delicacy was touching. One may have missed the shimmering whisper sustained by a Schwarzkopf in “Wiegenlied,” but Von Stade knows her way around a lullaby too. And she managed to invoke the broadest degrees of poignancy and rapture for “Morgen” without compromising the essential simplicity of sentiment.

The last song, not incidentally, was dedicated to the memory of Lucia Popp, the radiant Austrian soprano whose tragic death at 54 had been announced earlier in the week. Popp, frequently an ideal Susanna to Von Stade’s Cherubino, had graced the same Pasadena stage in comparably memorable recitals, most recently in 1991.

In Ginastera’s “Cinco canciones populares argentinas,” Von Stade exuded a perfect aura of sensuality, barely suppressed at the outset, incendiary at the close.

This was subtly counterbalanced by the voluptuous imagery of four melodies of Faure, counterbalanced in symmetrical turn by four quirky samples of English-language whimsy. Although the mezzo found much intimate cheer in miniatures of Charles Ives and Richard Hundley, she seemed most irresistible in the comic syncopations of William Bolcom’s “Amor.”

The program ended officially with two demonstrations of fragile Parisian romanticism--first the perfumed nostalgia of Thomas’ Mignon (“Connais-tu le pays?”), then the naughty erotica of Offenbach’s Grande-duchesse de Gerolstein (“Ah! que jaime les militaires”).

Three not-too-strenuous encores followed, in response to ovations from a partisan audience that had ignored the soloist’s obvious preference for silence between numbers in a set. Von Stade sustained Gallic chic with Poulenc’s “Les gars qui vont a la fete,” reinforced folksy pathos with Carol Hall’s “Jenny Rebecca,” and finally did a nifty chantoozie turn in Rodgers and Hart’s “Everybody Loves You (When You’re Asleep).”

Martin Katz provided magical collaboration at the piano throughout. Repeat: magical.