When Dave Chappelle promises to bring special guests, he means it.

The comic's four-hour concert Sunday night at Target Center was primarily billed as an opportunity for fans to see his new documentary film. But it turned into one of the Twin Cities' most unexpected pop events of the year when both Justin Bieber and Usher unexpectedly took the stage.

After screening the film, which celebrates Chappelle's efforts to operate an outdoor comedy venue during the pandemic, the headliner came out and did 15 minutes of material. Mostly, it consisted of telling Prince anecdotes and thanking Minneapolis for the way it responded to the killing of George Floyd.

"This city changed the world," he said, acknowledging that Floyd's family members were in attendance along with relatives of Daunte Wright and Emmett Till.

Comedy fans had to be disappointed that Chappelle didn't do much actual standup. But the evening was just getting started.

Moments after Chappelle wished the crowd a good night, Bieber marched out unannounced in a stocking cap and grunge shirt for four songs, accompanied by five musicians. He started "Peaches" at a keyboard, then moved to center stage, where he was soon joined by Usher, a mentor largely responsible for discovering him.

Bieber then took a seat alongside Chappelle right in front of the band as Usher seduced the crowd with four numbers of his own, including "U Don't Have to Call."

Neither artist spent much time showing off their trademark dance moves, although Usher did a few Michael Jackson steps that dazzled even from the nosebleed seats.

Chappelle wasn't about to let his famous friends call it a night.

For the next half-hour, he led an impromptu jam session that included snippets of Prince's "1999" and Eric B. & Rakim's "Paid in Full." The comedian doesn't have a terrific singing voice but that wasn't the point. Chappelle just wanted to keep the party going.

Near the end of the evening, he cajoled Bieber into performing "Love Yourself." Harmonica sensation Frederic Yonnet, whom Chappelle had as a guest during a 2016 Minneapolis after-party at the Aria Event Center, joined in. It was the evening's musical highlight.

Chappelle had a little less luck working his other big guest.

"Usher, stop being lazy!" he joked as he ordered the band to launch into "U Remind Me." About halfway through the song, the eight-time Grammy winner decided it was bedtime.

"I'm out," he said.

Chappelle's comedy guests weren't nearly as high-profile, but there was a little bit of something for everyone.

The evening opened with Pink Foxx, a saucy Los Angeles-based comic who is transgender. Her appearance seemed to be Chappelle's way of noting that not everyone in the transgender community was upset about the jokes he made in his latest Netflix special, "The Closer."

She was followed by Jeff Ross, who proved he deserved the title of "Roastmaster General" by inviting nearly a dozen audience members to the stage so he could destroy them with withering insults. In one of his gentler jabs, he mocked a middle-aged couple for looking like they got dressed for some Christmas decorating.

Also on the bill was Luenell, best known for playing a prostitute in "Borat." She slayed with a routine in which she re-enacted scenes from the TLC reality series "My 600-Lb. Life."

The film "Untitled," which is only available to watch right now on Chappelle's 10-city tour, also served a wide range of tastes.

For comedy fans, it's a chance to see high-profile stars like Jon Stewart and Tiffany Haddish relish the opportunity to perform amid a national quarantine, even if the venue was a cornfield in Yellow Springs, Ohio.

One of the most powerful story lines centers on comic Michelle Wolf, who basically moved in with the Chappelle family during the summer of 2020 and used her time in small-town America to do some self-therapy.

Directed by the Oscar-winning duo of Julia Reichert and Steven Bognar ("American Factory"), the movie also looks at how mom-and-pop businesses struggled to stay open last year and how Chappelle had to literally take on City Hall to get permission to keep his shows going. The crowd practically hissed every time the no-nonsense zoning inspector popped up on the giant screens.

It's clear why Chappelle made Minneapolis one of his tour stops. Floyd's death and the subsequent protests are referenced throughout the documentary.

At the very end of the event, Chappelle once again praised the city for leading the charge in making change.

"I am honored to stand in front of you," he said. "I'm at your service when you need me."

The tour continues Tuesday in Des Moines.