NEWPORT — As Jeff “Tain” Watts, the drummer of The Branford Marsalis Quartet, erupted into a solo during “Jack Baker,” the opening song of the group’s closing set at yesterday’s JVC Jazz Festival-Newport, bassist Eric Revis shouted his encouragement.

It wasn’t a soulful “Ow!” It wasn’t a jazzy “Yeah!” It was a guttural, ferocious “GO!” And Watts did.

It was that kind of set at Fort Adams. The quartet started in a furious, explosive gear most bands take half a set to get into, if they make it there at all. Even when the volcanic chaos faded away into the sweet “Hope,” with Marsalis picking up a soprano saxophone and with a long piano solo from Joey Calderazzo, or the jaunty urbanity of Thelonious Monk’s “Rhythm-a-Ning,” it was never far from the surface, coming back strong during the raucous closer “Samo.”

It was heady, challenging stuff. And it wasn’t the only example.

The second stage was closed by the Charles Mingus Orchestra, under the direction of Gunther Schuller, playing what he described as the bassist-composer’s “most difficult, most challenging, through-composed works,” such as “Taurus in the Arena of Life,” “Pithecanthropus Erectus” and “New Night” in an unusual ensemble including bassoon, bass clarinet and French horn.

There was solid bop from The Kenny Werner Quintet, and fast and furious trio jazz from Joshua Redman and a rhythm section of bassist Christian McBride and drummer Eric Harland in which there was no chordal instrument present and none needed. The Ben Riley Septet celebrated Monk with his sturdy rhythm and funhouse-mirror harmonies, the solo piano of Abdullah Ibrahim was trance-like without ever becoming simplistic, containing elements of the blues and the spiritual, and The Anat Cohen Quartet spun songs into spirals with the help of Cohen’s saxophone and, especially, clarinet.

Helped by great weather, the festival drew a crowd announced at 6,500, and the good turnout for serious jazz did festival impresario George Wein’s heart good.

“We got a real jazz audience,” he said, gesturing at the overflow crowd for the Mingus orchestra. “And it’s still the guts of what we’re doing, and that’s what we’re going to go for in the future.”

A couple of acts made noisy Newport debuts. Zap Mama, the world-music ensemble led by Marie Daulne, which started as an a capella quintet and has evolved into a full band with Daulne as lead singer, took awhile to get started literally and figuratively. Going on late, the group meandered, but eventually got going with Prince-style funk on “Sab Syl Ma,” which featured a touch of opaque vocal harmonies, and especially the closing “Toma Taboo.” An a capella “Go Boy” was sweet and mystifying.

Electric bassist Marcus Miller, whose career spans decades and hundreds of albums, made his debut with an enlivening set of basically instrumental R&B. The music was heavy on bass solos and accents, such as the fast runs and chordal fills on the opening “Blast,” from Miller’s forthcoming album (available so far only in Europe and Japan), and concluding with a blazing cover of The Beatles’ “Come Together.”

“It was tough but it was cool,” he said later of the show. “Playing in a fort, you know you’re around history.”

Dave Brubeck, who has done more Newport festivals than anyone, delivered his usual valedictory, with commentary and history accompanying the music. His son Dan, whose own Brubeck Brothers Quartet played earlier in the day on the second stage, filled in on drums for an ailing Randy Jones.

In his set, which included “Take Five,” virtually the national anthem of Newport, the elder Brubeck played a risky choice for an outdoor festival crowd — the lovely “Elegy,” with an extended flute and arco-bass unison from Bobby Militello and Michael Moore. “It’s a good festival,” Brubeck said before his set. “When you can do a full Catholic mass for a jazz audience,” he said, recalling his choral-jazz performance in 2004, “you know it’s intelligent people.”

Brubeck also sat in with his sons’ quartet on their closing “Blue Rondo a la Turk” and enthused (as enthusiastically as he gets, anyway) about his sons’ prowess. “Oh boy. It’s wonderful!”

Another bone-marrow drive was held yesterday, a reminder of last year’s effort in the wake of saxophonist Michael Brecker’s illness, which forced him to back out of that festival’s Steps Ahead reunion. (Brecker died in January, and his posthumous Pilgrimage album came out in spring.)

The registration drive drew more than 50 people, said Nicole Rubeira, of the Rhode Island Blood Center — behind the pace of last year’s 200 for the weekend, she said, but “it was a really great crowd.”

Drummer Jack DeJohnette, who played yesterday in a trio with McBride and pianist Bruce Hornsby, played on Pilgrimage and recalled the process as “very emotional, of course, but it was also challenging and a whole lot of fun. Mike was well aware he might never play again … he found the energy to do it.”

Hornsby is best known for his pop hits such as “The Way It Is” and his short tenure in The Grateful Dead, and has a degree in jazz studies. He said, of playing with McBride and DeJohnette, “It took me a while to get used to the feeling.… I was the one who had to get with it.”

At last week’s folk festival, beer and wine sales got their first tryout; the results were popular but the lines were long. Wein said at the time he’d fix the problem, and yesterday it looked as though he had; drink tickets were purchased at the same time IDs were checked, saving bartenders from making change, Wein said.

Chevy Chase was the titular host of the day’s events, but the buzz backstage was that he was in the midst of an unspecified family problem. He did a few intros from the main stage, but seemed distracted.

There aren’t any more huge jazz stars such as Duke Ellington, Miles Davis or Ella Fitzgerald, Wein said, so the days of 15,000-plus crowds are over. But yesterday’s turnout, for a largely challenging bill, gave him hope that a new audience can be built.

He gestured at the Mingus band in the midst of “Chill of Death.” “This is serious music up here.”

The festival continues today at Fort Adams.

rmassimo@projo.com