If Halloween had an official musical mascot, it would definitely be Primus—the band is fundamentally creepy and, as a bonus, Les Claypool rocks masks year-round. The California trio spent the holiday in New York this year as “Primus & The Chocolate Factory,” re-creating the soundtrack to Willy Wonka and the Chocolate Factory alongside a cellist and a marimba player/percussionist collectively called the Fungi Ensemble. Essentially, Primus won Halloween.

It all started normally enough: Claypool, guitarist Larry LaLonde, and drummer Tim Alexander stepped out in front of a plain black curtain around 8:15 and played Primus songs. The stage lacked decoration entirely, and Claypool teased the crowd by saying “Yep, we’re just going to play a regular set tonight.” The audience was into it—despite being in a seated venue, most people stood and headbanged—but there was a pervasive sense of anticipation for the Wonka freakiness to begin. Still, you can’t go wrong hearing Claypool hit his bass and sing about burying a body on “My Name is Mud,” especially on Halloween. After playing for a little more than an hour Primus left the stage and the Beacon Theatre’s plush curtains drew to a close.

We all knew what was coming next, yet we also didn’t know at all. “Primus & The Chocolate Factory” wasn’t a secretive event (i.e. Phish Halloween)—the band staged it on New Year’s Eve 2013 and recently released an album of the same name that re-interprets the 1971 film’s soundtrack. People came prepared in their best Wonka-themed Halloween costumes: there were multiple Willy Wonkas, Oompa Loompas, and even a Veruca Salt in the audience. After all, who doesn’t love a story about a magical candy factory, its bizarre candy maker owner, and a nice child winning over a bunch of terrible ones?

The curtains re-opened after a brief set break to reveal a stage inspired by the lush garden-like interior of Wonka’s factory—you know, the place where Augustus Gloop falls into the chocolate river. A massive inflatable mushroom towered over one side of the stage, and a bunch of smaller toadstools lined the floor on fake grass between Claypool and LaLonde. The Fungi Ensemble joined the band this time, cellist Sam Bass wearing a pig mask. The Wonka-land transformation was complete.

Primus’s take on the soundtrack is wildly different in the best, most twisted way possible. Claypool mutters the lyrics in his usual style; sinister guitar riffs and marimba solos (which elicited the loudest cheers from the audience) overtake the original’s show-tune vibe. Despite being geared at kids, Willy Wonka is a dark story, and Primus does the dark side its due justice particularly in formerly-super-peppy songs like “Candy Man.” Lest anyone not recognize the songs, a giant video screen above the band played looped clips of the movie with funky animations added in. So instead of one Veruca Salt bashing a giant piece of candy against a rock, we saw four of them (oh God) in a pinwheel formation.

“Golden Ticket” was a set highlight with its pounding drumbeat and Claypool yelling “I’ve got a golden ticket!” progressively louder as the song went on. During the iconic tune, an audience member dressed as Willy Wonka threw a bunch of homemade golden tickets over the edge of the balcony. The tickets glided down onto the heads of the people standing below and the Wonka dashed away before anyone could look up to see where they came from. Like a true Halloween saint, she made a bunch of audience members’ experiences exponentially trippier.

“Pure Imagination”—the song Willy Wonka sings to the children after they enter his factory—didn’t disappoint, either. Claypool ducked off stage and returned wearing a purple coat, top hat, and wig, designating himself the evening’s official alternate-universe version of the beloved Gene Wilder character. Claypool makes the ultimate creepy Wonka. Thus, hearing him sing the nonsense lyrics in the “Semi-Wonderous Boat Ride” over repetitive cello strokes was thrilling. LaLonde took the role of Veruca Salt during “I Want It Now,” brattily singing about wanting parties and ice cream.

Primus made sure to acknowledge the most integral part of the Willy Wonka experience: the orange-faced, green-haired Oompa Loompas. For each of the three “Oompa” songs in the set, two people wearing huge, smiling Oompa Loompa heads walked to the center of the stage and danced, bending slightly at the knees up and down, as the band played the wisdom-imparting songs. Each time the pair did the same dance, and each time the crowd went wild.

Toward the end of the set, Claypool shouted out Alexander—who, amazingly, had a heart attack and subsequent open-heart surgery just this past summer. Alexander was in top form and banged away while wearing a full-body costume: a white jumpsuit with goggles on top of his head, as per the scene in which Wonka brings his guests to his TV room and shrinks a chocolate bar (and a kid).

The Wonka set was about an hour long but satisfying nonetheless in all of its ghoulish, sensory-overload glory. Primus returned for a three-song encore of their own material before setting the crowd free to continue its Halloween revelry. Even in New York, though, it would be hard to find a delightfully weirder way to spend Halloween night.

Setlist for Primus Halloween at NYC Beacon Theatre | 10/31/14

Set 1

American Life
John the Fisherman
Last Salmon Man
Frizzle Fry
Jilly’s on Smack
My Name Is Mud
Jerry Was a Race Car Driver
Over the Electric Grapevine

Set 2

Hello Wonkites
Candy Man
Cheer Up Charlie
Golden Ticket
Lermaninoff
Pure Imagination
Oompa Augustus
Semi-Wondrous Boat Ride
Oompa Violet
I Want It Now
Oompa Veruca
Wonkmobile
Oompa TV
Farewell Wonkites

Encore

Too Many Puppies
Duchess and the Proverbial Mind Spread
Here Come the Bastards