VENTURA COUNTY WEEKEND : Legendary Charlie Byrd Bringing His Jazz Genius to Ojai : The man who helped popularize the bossa nova will perform a dinner concert at Wheeler Hot Springs.

Charlie Byrd, one of the original unplugged jazz heroes, celebrated his 75th birthday this year. But age is an elusive and possibly irrelevant matter when it comes to jazz musicians who have maintained a strong, personal voice.

For Byrd, that voice is one informed by classical, be-bop, pop and Brazilian idioms on the nylon-stringed, unamplified guitar, the instrument he will bring when he performs at Wheeler Hot Springs on Sunday.

Byrd was already in his 40s when his star took a sudden upturn, a shift that can be blamed on the bossa nova. Byrd’s Columbia recording, “Brazilian Byrd,” with music of the late Antonio Carlos Jobim and with horn and string arrangements by Tom Newson, made for a timely reissue early in the ‘90s.

Byrd’s biggest claim to fame in jazz history may be his role, along with Stan Getz, in popularizing the bossa nova with jazz-bossa recordings in the early ‘60s.

But there is more to Byrd than the bossa. In recent years, Byrd has been building up a catalog of recordings on Concord, the latest of which is a quintet recording, “Du Hot Club de Concord,” a tribute to Django Reinhardt, the Gypsy jazz guitar genius whom Byrd met and played with in Paris.

Although he was never a revolutionary, Byrd, in his own gentle melodic way, has done his part in expanding the vocabulary and the worldliness of jazz.

* Charlie Byrd in a dinner concert Sunday at Wheeler Hot Springs, 16825 Maricopa Highway, Ojai. Tickets are $50. Dinner starts at 5:30 and the concert at 7:30; 646-8131.

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Piano Dynamo: The flow of jazz in Ventura County has been, during the last few years, steady but modest, a well-modulated trickle.

This weekend, though, jazz lovers will have to choose between Byrd and the dynamic pianist Dorothy Donegan, who returns to the Thousand Oaks Civic Arts Plaza, also on Sunday night.

Donegan returns to the scene of last year’s musical fete, in a benefit concert sponsored by the American Assn. of University Women. If anyone has battled gender stereotypes, it is Donegan, a powerful female jazz player in a field where women generally have been restricted to vocal art.

Donegan, who began her long career in the bop era of the ‘40s, is one of those versatile wonders. Her technique incorporates the technical rigors of be-bop and classical, while never forsaking the earthier style of boogie-woogie and stride playing.

For a good primer on Donegan’s playing, check out “Dorothy Romps, a Piano Retrospective 1953-1979,” an album released on Rosetta a few years ago. “Lullaby of Birdland,” for instance, begins with clipped, classical decorum, but can’t resist the magnetic pull of swing. And so it goes, from Bach-esque and back, finally settling down into a bluesy halftime.

Both brainy and fun-loving, Donegan has a virtuosic command of the piano, but she’s also an entertainer without apology.

* Dorothy Donegan at 7 p.m. Sunday at Thousand Oaks Civic Arts Plaza’s Forum Theatre, 2100 Thousand Oaks Blvd.; 449-2787.

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Rochereau Fever: It’s safe to say that the hippest African musical emissaries residing in Anaheim are Soukous Kingpin Tabu Ley Rochereau and his L’Orchestre Afrisa International, an extended musical family.

Driven out of their native Zaire by a worsening political climate in 1989, Rochereau and his clan have enjoyed international acclaim, thanks to recordings on Peter Gabriel’s Real World label and an album last year on the Rounder label. Last year, they moved to the town Disney made famous, as a home base for a group that is constantly touring the globe.

But they touch down in Southern California occasionally, as they will at Matilija Junior High School in Ojai on Tuesday. Last August they performed an outdoor concert at Long Beach Art Museum. The band issued its undulating, rhythmically charged-yet-limber sound, over which Rochereau’s voice soared and testified.

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Tabu Ley Rochereau and his L’Orchestre Afrisa International, 7:30 p.m. Tuesday at Matilija Junior High School, 703 El Paseo Drive, Ojai. Tickets: $10 in advance, $12 at the door; 646-5163.