O.C. POP MUSIC REVIEW : Spirit Fills Show That’s Pure Ella : At the Performing Arts Center, the legendary singer proved that at age 72, along with her remarkable vocal refinement, she still has the vigor of a little girl, exploring and taking chances.

One might think that after a half-century of exemplary musicianship, Ella Fitzgerald might be willing to sit still long enough to let her fans just adore her for a while. Instead, the First Lady of Song’s appearance Monday at the Performing Arts Center found her racing ahead, as usual, like a child with new sneakers, exploring the back alleys of familiar songs and finding new corners to turn in well-traveled melodies.

The challenging invention and spirit that the 72-year-old put into her show could have shamed most performers a third her age. Her contralto may no longer be entirely as rich as it once was, but the soul that motivates it clearly is still as vigorous as souls get.

In a robed red satin suit, Fitzgerald came onstage to a thunderous standing ovation, which she acknowledged by saying, “Thank you, I hope you feel that way when I finish.” Any one of the 27 songs that followed justified the two ovations that closed out the evening.

Starting out with an earthy rendition of “Sweet Georgia Brown,” she and her excellent trio moved through a portfolio of great popular songs. She worked touches of Billie Holiday’s distinctive phrasing into “As Time Goes By” and displayed some of the late Sarah Vaughan’s penchant for fresh tempos on a jumping arrangement of “I Could Have Danced All Night” that closed out a medley of “My Fair Lady” tunes.

But mostly the performance was pure Ella. She has borne some criticism over the years for not being an especially emotional singer, with her voice not having the revelatory power over a lyric that Sinatra or Holiday exercised. It seems, rather, that she places her emotion elsewhere in the music. Sinatra may be the Olivier of song, with the light and shading of his voice bringing each word its sharpest definition; in Fitzgerald’s singing the words can become more like points of color she uses to create a miraculous musical abstract.

Even in her relatively straight song readings Monday there was a keen individualism expressed in gradients of timing and intonation, in nuances most contemporary singers seem not even to be aware of. Among the songs so honored were “Night and Day,” “Body and Soul,” Stevie Wonder’s “You Are the Sunshine of My Life” and medleys from the catalogues of Duke Ellington, Cole Porter and Lerner and Loewe.

It has been reported that Fitzgerald’s legendary scat singing began as a result of her not being able to remember lyrics, and it still seems her greater allegiance goes to notes rather than words. Though she appeared thoroughly engaged in the music during every second of her performance, the instances when she eschewed lyrics to engage in her hornlike scatting rose to an even higher level.

It shouldn’t go without mention that Fitzgerald has a wonderfully responsive trio in pianist Mike Wofford, bassist Keter Betts and drummer Bobby Durham. Both masterful and playful on their instruments, they were ideal companions for her excursions.

Intertwining her earliest hit, “A-Tisket A-Tasket,” with the Dizzy Gillespie bop standard “A Night in Tunisia,” Fitzgerald showed why her voice was accepted as a musical equal by the instrumental greats of several jazz generations, and why she is so loved by her fellow musicians. Along with all of her remarkable vocal refinement there is still the open spirit of a little girl, taking wild chances, waving her right arm in an excited impression of the melodic line, letting loose joyous whoops, growling, making percussive sounds, hot potato-ing musical figures with her band, and at one point even cupping a hand by her mouth and shouting, “Call for Philip Morris!”