New albums are viewed with hopeful skepticism by fans of bands with a long-cherished repertoire, and Phish’s Fuego was raked over coals even before it was recorded. The Vermont-born group debuted that new material last Halloween in place of an expected cover album — a cocky trick largely forgotten now that Fuego has been filtered through ex-Pink Floyd producer Bob Ezrin, its live, organic feel coupled with risky turns that makes it Phish’s most democratic and intriguing album since the ’90s.

Opening its summer tour at the Xfinity Center on Tuesday, Phish wasted no time in throwing down the gauntlet, tackling the album’s 10-minute title suite as the night’s second song. “Fuego” shifts from prog-rock with hearty choruses and odd lyrics (“Read a little book about Vlad the Impaler”?!) to a brisk breakbeat iced by pianist Page McConnell’s bubbling organ — and Phish nailed it. It foreshadowed a first set structured around four new songs, culminating in the dreamy gem “Wingsuit,” which swelled into Floyd-ish rock behind Jon Fishman’s deep drum fills and faded as Sudbury native Mike Gordon subtly vibrated a power drill against his bass strings.

A few old songs emerged in the middle of the first set. “The Wedge” included a call to “Take the highway to the great divide” that likely spoke to diehards who look beyond this weekend’s three-night stand in upstate New York to the tour’s August finale in Colorado. During a slithering “Stash,” fans interacted with the band through cued hand claps that evolved when Phish conquered the same shed 20 years ago to kick-start its second decade. And band members must have opted for the perky “Bouncing Around the Room” in response to the crowd batting a mammoth balloon before their eyes with the message “Thank you for 31!”

Just as newer songs dominated the first set, however, the second set flipped the equation to balance the night with an old-school blowout, from the set-opening surge of “Mike’s Song” through to the abstractly jammed funk of “Ghost,” which sped up and seamlessly dropped into “Weekapaug Groove.” Then a magnificent “Harry Hood” grew to 18 minutes as guitarist Trey Anastasio patiently steered into uncharted space with ping-ponging textures between the song’s neo-reggae wobble and gliding coda. Yet tucked in the middle of it all was another one of the best tunes from Fuego, the unusual ballad “Waiting All Night,” with Fishman taking the plaintive lead in band-wide vocals that split the gap between soulful and sappy with earnest sincerity.

Such a sense of naivety can be one side effect for musicians willing to step out on improvisational limbs and float new ideas. Tuesday proved a quick-settling clinic in jam-rock as Anastasio soloed with relaxed bravado, Gordon plied his spidery bass counterpoint, McConnell dug into his clavinet, and Fishman boldly churned away at his now-center-stage perch. Whether or not Fuego remains a true keeper, one can give these guys credit for trying — and on a night like this, it’s pretty effortless for them to keep rolling into a zone that most bands of their ilk only dream about.