The Cross Insurance Arena in Portland is a storied venue in the history of Phish. Music fans in Maine were early adopters of the Vermont band in the late 1980s and early 1990s, and the band’s New Year’s Eve run in 1993 – which partially took place at the arena, then known as the Cumberland County Civic Center – was a distinct moment when the band jumped up a level in popularity. Expectations are high whenever the band returns, and are frequently met. This time, though, during a string of shows that have frustrated the devoted fans who closely follow the tour in person or online, the results have been somewhat mixed.

Despite the sweltering arena, the crowd seemed ready to dance above all else. In the first set, the band misread the audience to a confounding degree. Groove-heavy songs such as “Cars Trucks Buses” and “Heavy Things” got a big response but were quickly diffused by ballads, songs that lurched and flopped in odd tempos, and mediocre late-career songs such as the undercooked “The Line” and “Yarmouth Road,” a mushy bit of reggae that sucked the life out of the room; the song’s writer and singer, bassist Mike Gordon, seemed to be the only person – and that’s counting the other band members – who enjoyed it.

Such miscues continued throughout the evening, in a show marked by nine songs written since the late-2000s. While the complaint of old rock bands playing new songs has been around as long as old rock bands have, in Phish’s case, it has some validity. With some exceptions, such as “Wingsuit,” the newer songs are not particularly challenging. They’re marked by simple melodies and basic verse-chorus-verse structures, sometimes enhanced with the kind of jam that the band can now perform without effort, like an experienced pilot landing a plane. The older songs, no matter how familiar to their fans, still sound as if they’re more challenging for the band to play, and more surprising for the audiences to hear. This jackpot combination of familiarity and unpredictability is what gives the band’s shows an edge that keeps people coming back. But the newer songs, ironically, feel more familiar than the old ones.

As if to make up for an awkward first set, the band played a monster of a second set, packed with heavy hitters such as “First Tube,” “Fluffhead,” and “Weekapaug Groove.” These classics were well-played if a bit conservative – “Mike’s Song” and “Tweezer” are traditionally the band’s biggest jumping-off points into the unknown, but here they played them close to the vest. Nonetheless, all these songs are engineered for highly satisfying concert experiences, and that’s exactly what they provided. Aside from a lull in the middle, it was not unlike a great DJ set, as the band eased the audience through dense grooves, ambient textures, blissful peaks and arms-in-the-air moments.

Encouragingly, the best of the new songs were the ones that have yet to appear on any album. “Tide Turns” is slow and sweet to the point where many fans will resent it, especially when dropped after a heavy, second-set “Mike’s Song,” as the band did last night. But it’s a structurally sophisticated and emotionally affecting composition – the best thing that Trey Anastasio has written in some time. “Blaze On” rides a crowd-pleasing beat reminiscent of “Iko Iko,” while “Things People Do” is a blistering and brief bluegrass number, the likes of which they used to uncork with regularity. These songs point to a bright future as the band members all settle into their 50s. Hopefully, however, they don’t entirely abandon the extended improvisation that got them here.