With a multi-octave voice equal to none, incredible scatting skills and ease of transition from a throaty whisper to high-pitched trills, vocalist Cleo Laine remains one of the jazz world’s fascinating attractions.

At age 78, her ability to captivate and entertain an audience is as sharp as it was when she burst onto the worldwide concert stage some four decades ago. That and the enduring love affair with husband/arranger/saxophonist John Dankworth were on display for a receptive audience that turned out last Saturday night at the Napa Valley Opera House to take in a performance by the “royal” couple.

This was not the first time Laine and Dankworth have entertained wine country fans. In 1992, the pair teamed up for a memorable concert at the Robert Mondavi Summer Music Festival.

For those who might not know the vocalist, Laine was born in 1927 in the Southall section of London, the daughter of a Jamaican father and English mother. Her parents sent her to vocal and dance lessons as a teenager, but she was 25 when she first sang professionally, following a successful audition with a big band led by John Dankworth. In 1958, she was married to Dankworth.

With Dankworth by her side, Laine began her solo career in earnest with a 1964 album of Shakespeare lyrics set to Dankworth’s arrangements, “Shakespeare: And All that Jazz.” Laine also gained renown for the first of three concert albums recorded at New York’s Carnegie Hall, 1973’s “Cleo Laine Live! At Carnegie Hall.” She also recorded two follow-ups (“Return to Carnegie” and “The 10th Anniversary Concert”).

In 1986, she became the first-ever British performer to win a Grammy Jazz Award (Best Female Jazz Vocalist) for the third of her live Carnegie Hall albums. Ella Fitzgerald, who Cleo had met on an early U.S. tour with the Dankworth Big Band, sent a bouquet of roses and a card, which echoed in the simplest terms exactly what everyone was thinking. It read, “Congratulations gal — it’s about time.” In fact, Laine has since gone on to become the only female singer ever to have been nominated in the pop, jazz and classical vocal categories of the Grammy Awards, a testament to her incredible virtuosity. However, Laine was not able to collect her award in person on Grammy night. She was on Broadway portraying the mischievous Princess Puffer in “The Mystery of Edwin Drood,” which secured her a nomination for a coveted Tony award.

Other accomplishments include a jazz version of “Porgy and Bess” with Ray Charles, as well as duets with flutist James Galway and guitarist John Williams. Laine and Dankworth continue to tour all over the world. She received perhaps her greatest honor when she became the first jazz artist to receive the highest title available in the performing arts, dame commander. And earlier this year, John Dankworth received a knighthood for his services to music.

The first segment of Saturday night’s program featured Sir John Dankworth and three exceptional Bay Area jazz musicians who appear regularly with the noted composer and saxman — pianist Larry Dunlap, bassist Seward McCain and drummer Jim Zimmerman.

The quartet wove a magic spell of Tin Pan Alley classics — ranging from “Stompin’ at the Savoy” to Duke Ellington’s “In a Mellow Tone” — for about 45 minutes, with all hands given ample opportunity to strut their stuff.

Following intermission, Dame Cleo Laine offered a short-but-sweet set of material representative of her lengthy career. Smartly garbed in a gorgeous gold-trimmed black velvet gown, Laine kicked off her hour-long program with a medley of Vincent Youmans songs from the Roaring ’20s — the haunting ballad, “Without A Song,” and “I Want to be Happy” from the Broadway show, “No, No Nanette.” She excited local fans right off the bat by scatting note for note with her husband on the latter number.

Laine reminded us of the incredible recording she made with Dudley Moore in 1982 by offering another shimmering medley — “I Don’t Know Why (I Just Do)” and “Love Me or Leave Me.” And there were a couple of those incredible Shakespeare sonnets that Dankworth set to music for his wife decades ago.

Those who hadn’t heard the 1976 Cleo Laine and Ray Charles recording of George Gershwin’s “Porgy and Bess” were treated to an exceptional rendition of “I Got Plenty o’ Nuttin’.” And she did a bang-up job conveying Dave Frishberg’s tongue-in-cheek picture of a high-maintenance relationship, “Peel Me a Grape.”

Wrapping up their current tour of the country and heading home to England, Laine, Dankworth and company left the appreciative Napa crowd in the warm glow of Duke Ellington. The composer’s “Creole Love Call” proved to be the most famous recording in the career of American-born British singer and entertainer Adelaide Hall. Hall would have approved of the classy arrangement and reverential vocal approach to this big band classic from the Roaring ’20s. For an encore, Laine ripped through Ella Fitzgerald’s lyrics to the beloved Duke classic, “It Don’t Mean a Thing if it Ain’t Got That Swing.”

And the evening sure had lots of swing. For this talented couple, time stands still. Age be damned, Dankworth and Laine are still at the top of their form.