Expect the unexpected. That's been the name of the game for Totally Gross National Product, who for three years running have produced a masterfully chaotic showcase of their label's talent and this year threw their largest party yet at new Nicollet Ave hotspot Icehouse.

If anything could further cement Totally Gross label operators Ryan Olson, Drew Christopherson, and Max Lasker's position at the epicenter of some of today's most exciting local music, it was Sunday's eight-hour, two-stage extravaganza. It was easily the most centralized display of their curatorial powers since they held court at Nick and Eddie a few summers ago, and reignited the spark of cross-pollination and collaboration that was lit back when Marijuana Deathsquads and Gayngs started to play live shows.

Unadvertised sets by P.O.S., Poliça, and Solid Gold lit up Twitter and helped to sell out the club on a school night, but the appeal of this marathon show extended far beyond its big-name headliners.

An early set by Votel on Icehouse's patio stage was a highlight, with Maggie Morrison looping her vocal acrobatics over smokey, pulsing beats. The group has made great progress in refining their sound over the past two years and focused their set around a handful of well thought-out compositions. It was a reminder of the great strides they had made together before beatmaker Drew Christopherson started touring nonstop with Poliça, and it made me hopeful that they'll find a way to play out more frequently in the future.

The Clerb drew one of the largest crowds on the free outdoor stage, with MCs Mike Mictlan, Lizzo, Spyder Baybie, and La Manchita performing a nonstop, raucous round-robin of rap music. They were followed up by another more somber set of hip-hop by Andrew Broder and rappers Mictlan, Crescent Moon, and MaLLy; I'm hoping that configuration of players returns to the stage together soon, as their set passed far too quickly.

Another standout set came from Leisure Birds, who have almost entirely rebooted their garage rock into an expansive prog-inspired project. On some of the newer songs, the only familiar component was lead singer Jake Luck's high-register hollering, while on others they combined their garage roots and pulsing synth explorations to create a stunning new swell of sound.

Speaking of new sounds, Solid Gold used the opportunity to perform mostly unreleased material, with the group's three core members bolstered by brothers Jake Hanson on guitar/backing vocals and Jeremy Hanson on drums. The Hanson brothers have always been active in many different projects -- this was made especially clear to me this past weekend as I saw Jake perform in four different acts in less than 36 hours -- but it also seems that they have begun to perform together more as a unit, with both of them now steady members in both Solid Gold's live band and Actual Wolf.

A new Solid Gold record has been in the can for a while now, and on Sunday night members hinted that it might be released as soon as October 30. Given how long the band has lingered between releases and shows, it'll be a relief to see them win back some of their early-career momentum.

Poliça performed a short, experimental set that began with a stripped-down reimagination of "Happy Be Fine" that was built around a "Purple Rain"-channeling electric guitar part. The next song was brand new and showcased the band's intent to use Channy Leaneagh's gauzy voice as more of an instrument than the central focus of their sound, building up a pillowy cloud of sound around her searching melodies. They followed it up with another pair of new songs that they have been performing live, then dissassembled and transitioned seamlessly into a Marijuana Deathsquads set played from the floor in front of the stage.

Drummers Drew Christopherson and Ben Ivascu stayed in their seats and provided the thundering backbone for Deathsquads' set, and Leaneagh lingered on stage to pepper vocals over the top of their first song before retreating to give the spotlight to vocalists Isaac Gale and Stef Alexander (P.O.S.) and DJs Ryan Olson and Mark McGee. As the set progressed it became apparent that there were actually three layers of sound being contributed, with the drummers on stage and the vocalists and DJs on the floor being accompanied by live scratching by DJ Plain Ole Bill up in the balcony. To my ears, this point in the night was among the most exhilirating of the evening, but the crowd started to thin out as they played, either overwhelmed by the cacophony or just unable to stay out any later on a Sunday night.

Those who left during Deathsquads missed the last surprise of the evening: An eight-song solo set by P.O.S., who used the inimate gig to test out his new material prior to next month's album-release show at First Avenue. After a brief interlude on the floor by Slapping Purses, DJ Plain Ole Bill cued up tracks off P.O.S.'s forthcoming We Don't Even Live Here from his spot in the balcony while Mike Mictlan stood at side stage, waiting to jump up and contribute to bangers like "Get Down" and "All of It."

P.O.S. sensed that the crowd was growing weary after so many hours of music, and at one point jumped down into the crowd to coerce the night owls to dance just a little bit longer. But even he seemed to be holding back a bit, leery of spoiling his fans' appetite for more from him this fall. During the dizzying build of "Lockpicks, Knives, Bricks and Bats," he raised his hand to his throat and signaled for Bill to cut the music.

Looking out at the sweaty crowd, he shrugged and laughed. "Better save something for the release show."