Usually it’s the indie-folk whippersnappers who dominate the collaborations that now grace Rhode Island’s revitalized Newport Folk Festival. But in celebrating her recent 75^th birthday, headliner Mavis Staples wasn’t about to cede her reign and miss out on whimsical possibilities at Fort Adams State Park this past weekend.

The gospel-soul icon, who debuted at Newport with the Staples Singers in 1964, proved robust in personality and voice, testifying with her band on Sunday to chase away the sporadic rain. Yet Staples was busy visiting other stages on all three days of the festival, sitting in with the Boston-bred Lake Street Dive on Friday and then Lucius, Puss N Boots and Jeff Tweedy, the producer of Staples’ latest albums.

Lucius’ Jess Wolfe and Holly Laessig, who turned heads with their Berklee-trained band’s mashup of girl-group vocals, grungy sonics and tribal percussion on Saturday, also enjoyed their popularity. They returned Sunday in matching glittery dresses and platinum-blonde bobs to sing with both Staples (for a delirious sendup of Talking Heads’ “Slippery People”) and Wilco leader Tweedy, who’d drafted the Lucius gals for his upcoming solo album with drummer son Spencer. The Tweedys’ band dipped into that material Sunday along with Wilco gems capped by “California Stars,” a song spun from Woody Guthrie lyrics. And Staples rounded out her set with guests that included Tweedy, Lucius, Trampled by Turtles and Norah Jones (who dealt modest charms in Puss N Boots the day before), closing with “We Shall Overcome,” a salute to festival favorite Pete Seeger, who died early this year.

Before Staples’ triumph, the festival seemed to revolve around the rock star-like presence of Jack White. He strode the grounds on Saturday to check out various stages (at times accompanied by actor-performer John C. Reilly) and during his day-closing set, White said he was impressed by how people didn’t bother him. Not that he was that inapproachable. When one fan with posters waved toward the briskly walking White, the musician motioned to catch up for a quick autograph. White’s set proved a bit shambolic though. He romped about the main stage, swapping between electric and acoustic guitars as he mixed and mashed blues standards with tunes from his White Stripes and solo catalogs, sounding like Led Zeppelin on ADHD with a likewise-manic foil in off-kilter drummer Daru Jones. White also played piano on two tunes, including a momentum-stifling “The Rose with the Broken Neck” (from the soundtrack-ish Danger Mouse project Rome that also featured Norah Jones) before ripping up his Raconteurs rocker “Top Yourself.” On the other hand, he tickled with the Stripes’ country two-step “Hotel Yorba” (co-sung with fiddler Lillie Mae Risch) and the lovely “We’re Going to Be Friends.” And for his finale, he invited out folks including Pokey LaFarge and the Milk Carton Kids for “Goodnight Irene.”

White (who saved his own sit-in to join Beck in Providence that night) also unleashed an odd diatribe against the dangers of seeking authenticity. “Authenticity is a phantom,” he warned Saturday’s crowd at the long-soldout festival. “It doesn’t matter about [someone’s] clothing or hair. It’s about the music.”

That comment made sense with Valerie June, who took the smallest stage in a maze of dreadlocks, a sparkly dress and turquoise cowboy boots, and began with the solo banjo blues of “Rollin’ and Tumblin.’” The Tennessee native’s keening vocals had an Appalachian twinge, though her country-folk (filled out with fiddle and standup bass) echoed modern R&B as well.  Other audience-building upstarts included Shakey Graves (a singer/guitarist who played a suitcase kick drum with his heel) and Hozier, an Irish singer/songwriter who led a larger band with cello but relied on resonant low dynamics and piqued interest with his viral hit “Take Me to Church,” which targets orthodox hypocrisy. Guitar fans soaked in bluesy rocker Benjamin Booker and the stomping flamenco duo Rodrigo y Gabriela, who were a crowd-thrilling whirl of motion and metallic fret-speed on acoustic axes.

Newport returnees also impressed, from the fiddlin’ folk-blues of Hurray for the Riff Raff (led by the beaming Alynda Lee Segarra) and rambunctious bluegrass of Trampled by Turtles to the delicate folk-pop of Milk Carton Kids, a hushed duo of harmonizers in the Simon & Garfunkel mold, all on the middle stage inside Fort Adams. Others graduated to early main-stage slots, including Shovels & Rope, a husband/wife duo that swapped guitar and drum kit only to sound full and feisty, and Rhode Island’s own maturing Deer Tick, who arrived in matching white sailors’ outfits, backed by a horn section. Back from a seven-year hiatus, the popular bluegrass-rooted trio Nickel Creek mixed deft picking and streamlined pop appeal with its hit “Destination.” And the charismatic Conor Oberst forged one of Sunday’s best-sounding sets, with smart backing by the band Dawes and well-balanced orchestration from horns and backup singers.

And that was just a taste of what was happening on Saturday and Sunday around the walls of Fort Adams, where you could also browse the vendors booths and see the Decemberists’ Chris Funk hanging out, looking easier to talk to than Jack White. From lineup to settting to vibe, Newport Folk continues to earn its stripes.