Jazz, like the country of its birth, is forever a dazzling work in progress. The genius of that progress for more than six decades, improvisations, reinventions and all, is embodied in Dave Brubeck’s music. He helped ease jazz into the mainstream, married spontaneity with classical rigor, made unlikely time signatures irresistible, and he made very serious music swing. From the Dave Brubeck Quartet’s worldwide success in the 1950s and ‘60s, right through the jazz opera Cannery Row Suite he created with his wife Iola Brubeck at the 2006 Monterey Jazz Festival, and Brubeck’s piano solo prowess at the 2008 San Francisco Jazz Festival, the man continues to surprise.

He has set to music the words of the Old Testament and of Martin Luther King, Jr. He has created the sounds of Peanuts in the miniseries This is America, Charlie Brown.  He has inspired choreography by Lar Lubovitch, Murray Louis and other visionary dancemakers. His “polytonality and use of polyrhythms, combined with his uniquely American musical language,” noted The New York Times, “give his music an unmistakable and accessible sound.”  Crowned “the reigning elder statesman of jazz” by the Washington Post and designated nothing less than a “Living Legend” by the Library of Congress, this octogenarian icon of West Coast cool remains impossibly young.  That’s jazz for you.

”I am primarily a jazz composer. Most of us don’t even like the word jazz—Ellington didn’t like it, Stan Kenton didn’t like it. It’s really an extension of what Bach and Mozart did every day: improvise. Bach improvised every Sunday. Classical music shouldn’t abandon it. The composers most likely to live on from the 20th century are Ives, Copland, Bernstein, Ellington, Gershwin and all the people wise enough to use jazz, like they were.”

”As Darius Milhaud said,” Brubeck told The New York Times recalling his mentor, “if you come from America and haven’t felt the jazz influence, then you haven’t written music that expresses America.” Dave Brubeck, unmistakably, irresistibly, writes American music.

David Warren Brubeck was born in Concord, California in 1920 into a musical family. He began piano lessons with his mother at the age of 4 and by 14 he was playing local gigs on weekends. He enrolled in the College of the Pacific in Stockton, where he met his future wife, fellow student Iola Whitlock. After graduation in 1942, he enlisted and served in Patton’s Third Army in Europe. After the war, the young veteran enrolled in Mills College in Oakland, studying composition with Darius Milhaud. It was the jazz-loving French composer and adopted Californian who encouraged Brubeck both to pursue a career in jazz and to incorporate jazz into his compositions. The first Dave Brubeck Octet, a musical gathering of Milhaud’s students, was formed in 1947. In 1949, with Octet alumni Cal Tjader and Ron Crotty, Brubeck made the first of a string of award-winning Dave Brubeck Trio recordings. He teamed up with the saxophonist Paul Desmond, another octet alumnus, in 1951, beginning a collaboration that would influence jazz for an entire era.

With Eugene Wright on bass and Joe Morello playing drums, Brubeck and Desmond played college campuses and concert halls, introducing cool jazz to a post-war generation, and touring with such giants as Ella Fitzgerald, Duke Ellington, Charlie Parker, Dizzy Gillespie and Stan Getz.  Brubeck’s portrait appeared on the cover of Time in 1954, with a story about the rebirth of jazz and the Dave Brubeck Quartet’s popularity and heralding Brubeck as the leader of “the birth of a new kind of jazz age in the U.S.”  Sponsored by the State Department, the Dave Brubeck Quartet began touring internationally in 1958 and took American jazz to Poland, India, Turkey, Sri Lanka, Afghanistan, Pakistan, Iran and Iraq. Their recordings made musical history: Time Out in 1959 declared jazzy independence from the traditional 4/4 rhythm, giving birth to the now classic 5/4 time “Take Five,” the 6/4 “Pick Up Sticks,” and the disarmingly fresh “Blue Rondo a la Turk” in 9/8. Composed by Desmond and boasting dry and witty banter between the soloists, “Take Five” began turning up in jukeboxes all over the world. Time Out became the first jazz album to sell more than a million copies. Now in the Grammy Hall of Fame, it remains one of the best-selling jazz albums of all time.

Even as he continued to explore the intimate possibilities of his Dave Brubeck Quartet, the composer followed Milhaud’s advice and expanded classical music’s horizons with jazz.  He recorded Dialogues for Jazz Combo and Orchestra with Leonard Bernstein and the New York Philharmonic in 1959, and in 1960 he composed Points on Jazz for American Ballet Theatre.  He began a fruitful association with the Murray Louis Dance Company. He composed the musical theater score The Real Ambassadors for Louis Armstrong and Carmen McRae, who made it a hit at the 1962 Monterey Jazz Festival.  As his family grew, Brubeck performed with his sons Darius, Chris, and Dan, billed as “Two Generations of Brubecks” and boasting the saxophones of Desmond and Gerry Mulligan as guests. The Cincinnati Symphony Orchestra premiered Brubeck’s oratorio The Light in the Wilderness in 1968 and soon afterwards his cantata The Gates of Justice, a setting of words by Martin Luther King, Jr.  President Johnson invited Brubeck to play at a state dinner for King Hussein of Jordan, and the jazz master soon became a familiar player at the White House for many administrations. He accompanied President Ronald Reagan to Moscow and played for the Reagan-Gorbachev summit in 1988.

A devout Catholic, Brubeck composed Upon This Rock for Pope John Paul II’s visit to San Francisco. His mass To Hope! A Celebration, has been played in Vienna’s St. Stephen’s Cathedral and in Moscow with the Russian Orchestra. On April 8, 2008 Secretary of State Condoleezza Rice presented Brubeck with the Benjamin Franklin Award for Public Diplomacy for offering an American “vision of hope, opportunity, and freedom” through his music. He is America’s cultural ambassador in the best sense, a musical messenger of optimism and hope, of the freedom that is jazz itself.

Dave Brubeck turns 89 years old this Sunday, and he gets this birthday-party favor to hang around his neck, a trifle of a thing, really, a rainbow-striped ribbon award to join all the other degrees and honors trailing the great living jazz legend.

Never thought it would happen, Brubeck says. Why not? He smiles. He shrugs. Who knows? It’s lovely, he’s pleased, it will be a nice evening, “a last hurrah,” says Iola, Brubeck’s wife of 67 years and his collaborator and lyricist.

They are in a hotel suite in Minneapolis, he in stocking feet, white shirt, khaki dress pants and suspenders, doing this interview, she in black sweater and slacks, silk scarf about her neck, peering at a laptop at their autobiography, now in progress for at least a decade. An easy, slow afternoon late in the autumn of a remarkable life and partnership. If you were scoring at home, perhaps you’d open with a reverie in waltz time, each note a lingering, almost melancholy kiss.

Brubeck would be good with your intro for maybe 16 bars.

Then he and his sidemen would crack that ballad wide open in a hard-charging, swinging version in a time signature you couldn’t hope to count out, you’d just have to close your eyes and hold on. That is how Brubeck is. That is how he plays. That is how he lives, in stubborn and sunny defiance of all conventional rhythms of jazz and age itself.

An afternoon in a hotel room will yield to a night in a club, on this night in early November at the intimate Dakota jazz supper club in downtown Minneapolis, five sold-out sets over three days, the audience jumping to its feet in ovation after every one, no set the same, ever, among four guys who have been playing together for years.

“Last night,” he says, “we even played something we don’t know!”

What possible tune could the Dave Brubeck quartet never have played together before?

“After ‘I Cried for You,’ I called ‘Take Me Out to the Ballgame’! Sounded pretty good, too!”

“You know my team is in the World Series?” I prompt, and we both cry out the punch line to the old bar piano player joke: “No, but hum a few bars and I’ll fake it!”

Brubeck grins widely, rests his huge hands on his knees. Of course there is no way to stump this piano player. The man has been performing and composing, improvising freely across genres for some 70 years, mixing jazz with sacred and classical forms, recording hundreds of times, with his original quartet, whose 1959 “Take Five” improbably became the first million-selling jazz single of all time; with his own sons; as a soloist and with chorales and full orchestra. He continues to compose with urgency, scribbling on manuscript with pencil. With his son Christopher, he’s tweaking the score for a multimedia work about the photographer Ansel Adams that the Baltimore Symphony will present in February; there’s also some piece for 20 cellos.

Sitting in a Kennedy Center opera box in his tux listening to everybody else play his music is not his favorite way to spend a night. He wants to play. He lives to play.

While other honorees were easing toward the Mandarin Oriental Hotel on Friday, the Dave Brubeck quartet was getting ready for a gig that night. In Cranston, R.I. In a Catholic church. And it was not a “give ‘em ‘Blue Rondo’ and send ‘em home happy” gig. Rather, the group was to combine with 60 Providence Singers to perform “Canticles of Mary,” a complicated work in which he offers a prelude hymn and then employs three Gregorian chants in three separate movements. But because this is a Brubeck composition, of course the choir has to sing all four themes simultaneously in the finale.

In fact, he never has attended a Kennedy Center Honors evening, even though he gets invited every year and was on the selection committee. He finds special pleasure in the symmetry of receiving his honor from President Obama, whose father, Obama wrote in his memoir, took the 10-year-old Barack to a Brubeck concert in Honolulu during their only visit together. (“I struggle to sit quietly in the dark auditorium beside him, unable to follow the spare equations of sound that the performers make, careful to clap whenever he claps,” Obama wrote.)

Each December when the honors weekend rolled around, Brubeck was always working. “You know, traveling across the country, traveling blues . . . ,” Brubeck says. “You know ‘Traveling Blues’?” He sings, drumming on his knees, “ ‘. . . I check into a hotel and then forget its name. Guess I could ask but, oh well, aren’t all hotels the same?’

“Iola wrote those lyrics. I recorded it with Carmen [McRae]. Iola and Carmen always had a melding of the soul. I loved playing behind Carmen.”

He loves playing, period. Anything, everything, any night he can. Listen to Brubeck live or recorded, and it’s all there in exuberant disregard for rules: The Caribbean “jump up” road march of Easter Morning, the minor laments of klezmer, the quote of the Disney theme “Someday My Prince Will Come” in the middle of the Turkish street beats of “Blue Rondo,” dervishes, soldiers, Bach.

A little music theory tutorial from Dave Brubeck, who is quite the showman even when speaking, a cappella:

Have you ever heard of the Dennis-Roosevelt expedition into the Belgian Congo?” he asks the crowd at the Dakota on the third night of the quartet’s stand there. No, they have not. But they are rapt and at attention. He pauses. “Well, none of it was in 4/4,” and the whole room breaks up, bandstand included. “Africa is a lot more complicated than that. Miles knew it. Bill Evans knew it. Even though people thought we were getting away from jazz [back in that seminal year of 1959] we were doing what jazz was always supposed to do, which is overlay time signatures.

“Now this next piece is in 10/4.” Pause. “I thought that when I wrote it, it was in 5/5.” And now the audience is laughing.

And later: “This piece is called ‘40 Days.’ It starts in 4/4, but don’t let that fool you.” More laughing, chuckles from alto saxophonist Bobby Militello, drummer Randy Jones and bassist Michael Moore. “It goes into 5.” Pause. “We hope.” And “40 Days” comes with yet another overlay time signature, the gentle clanking of silverware.

Yet Brubeck is a most deeply conventional syncopated man. He prefers “baloney!” and “you bet” to coarser declamations. He doesn’t drink, doesn’t smoke, regards mournfully the drugs that ravaged the other geniuses of his generation. Perhaps the prodigious work ethic and discipline that harnesses his creativity grew out of rhythms a boy couldn’t mess with, the needs of horses and cattle and people on the 45,000-acre ranch his family lived on in rural California. “Dad used to wake me up in the middle of the night to fill the woodbox,” he recalls.

It was his musically gifted mother who taught David, Howard and Henry, also musicians, to play piano, and it was she who insisted that David go to the College (now University) of the Pacific, and, once there, worried he was becoming a hermit. Take a girl to a dance, she said. Brubeck asked his roommate which girl was the brightest, and then he sent the roommate to approach Iola Whitlock. After some dancing, recounts Russell Gloyd, a conductor and former trumpet player who is Brubeck’s longtime manager, David suggested they just talk. After three hours, they had decided to get married.

Then Brubeck went off to World War II, a sharpshooter who could play piano at the front. On D-Day, one of the many friends who died in the war was shot in the harness of his parachute as he floated to earth. Young Brubeck’s anger and anguish deepened into faith and gratitude and an obdurate optimism that has driven him forward, a humanist, ever since.

When that is what you experience as a young man,” says Brubeck, “you tend to greet each day ever after happy to have awoken.” He always has known that music must be imperative for humans, because they create it. One night in a hospital bed 20 years ago, he was reflecting on the heart, his own, scheduled to be opened up to the surgeon’s knife the next morning. He was composing, as usual: “Psalm 30,” which he then dedicated to the cardiologist. He concluded that all rhythm begins, literally, with the heart—“pa-DUM, pa-DUM,” he taps on his knee—its pacing changes, from emotion and duress, across climes and continents, perhaps accounting for the ethnomusical variations across the world.

“It is the very first sound a baby hears,” Brubeck notes, “and the very last sound the body makes before it expires.”

As he listens to his own, with the wisdom of long life, his own playing sounds ruminative and interpretively richer. A bout of tendonitis afflicted three fingers of his left hand earlier this year, but, as Gloyd points out, “when some fingers aren’t working for a jazz musician, he can work around them.”

“Indian Summer,” Brubeck’s acclaimed solo release in 2007, is absent the density of flourishes and technical runs that defined his vigorous earlier playing. But this has allowed him to reinterpret, to explore the depth of the compositions.

“Dave is not slowing down,” says Gloyd. “He’s re-evaluating.”

And any somber or wistful moments, any hint of a permanent goodbye, yields always to a strut or a glide down the sunnier side of the street.

At the Dakota, Brubeck announces from the stage: “I wanna say, just follow me. I don’t know where we are going, just follow me.

Three of these four guys have been playing together nearly 30 years, longer than most marriages. One’s too old, one’s too fat, one smokes too much, one married too much.

And on this third night at the Dakota, they are still unbelievably hot, still tight, still swingin’, still smokin’. How is that?

After 100 non-stop minutes, with the audience whooping, there comes the signature finale, “Take Five,” a tune they’ve played thousands of times. Tonight, there’s an extended Brubeck piano solo intro that no one has heard before. There are some dulcet, soaring quotes of “These Foolish Things” from Militello.

At the tune’s end, Brubeck stops playing under the concluding drum solo entirely and sits on the bench, his back brace a faint line under his tux jacket, beating out the time on his thighs, his face split open with his huge smile. It’s a stomp, a roll, a praise-the-Lord drum line, an African tribal shuffle, from one man, this white drummer from London, in a club in Minneapolis. The room loses its collective mind.

“Where did that come from?” Brubeck crows in the green room as soon as everybody’s off the stage. “That might be the best set we’ve ever played in our lives!”

The honor is lovely, but this? This is a happiness approaching ecstasy. And even better, if the music you just played might be the best set you ever played, the set you play tomorrow has the potential to be even better.