With a barrage of pyro, a flood of smoke and deafening “Posty” chants from an enthusiastic crowd of kids, parents, inebriated 20-somethings, even Forum security staff, there he is: Post Malone, all alone onstage, destroying a guitar and pouring out two solo cups of what we can assume is Bud Light, finishing off his hit “Rockstar” — and fully living up to the title.

It’s only been four years since “White Iverson,” the breakout song that introduced Post to the world, which almost doesn’t seem possible considering the parade of hits he’s pumped out since then. Those hits made up a big chunk of his his 21-song set on Wednesday night, spanning all three of his studio albums — 2016’s “Stoney,” 2018’s “beerbongs & bentleys,” and this year’s “Hollywood’s Bleeding” — and showcasing his range, both as a vocalist and songwriter.

After building suspense with a slow-to-rise lighting rig and biblical amounts of dry ice, Post opened the show with “Hollywood’s Bleeding,” a fitting start for an L.A. gig. Even though the song wasn’t released as a single, the crowd sang along with every word.

After an energetic burst of “Better Now” and a trip to “Saint-Tropez,” the melancholy Posty came out. “This song is about feeling like sh–: Having your heart broken but still not being able to say goodbye,” he explained before plunging into “Goodbyes.” To go from “Versace boxers on my d–k / Bud Light runnin’ through my piss” (“Saint-Tropez”) to passionately belting out “Say you needed this heart and you got it / Turns out that it wasn’t what you wanted” (in “Goodbyes”) sums up the Post dichotomy perfectly. He is the face-tattooed, beer-pong playing, croc-designing “f—in’ hoes and poppin’ pillies” dude that writes killer hooks, as well as the “Tell me that it’s all okay,” and “I fall apart / Down to my core” emotional wreck. He’s a complex artist that can succeed in both of these aspects of being authentically human.

That dichotomy speaks to his music as well, with the emo and rock influences in alternative-leaning tracks like “Allergic” and “Take What You Want,” accompanied by a video of Ozzy Osbourne’s feature on the track. He also got The Forum into party mode with bangers like “Go Flex,” “Wow,” and “Psycho.”

But on this tour, the softer, more vulnerable songs is where he shines vocally and got a massive reaction from the crowd. Dedicating “I Fall Apart” to “anyone who’s ever had their heart broken,” he tackled the track with a signature quiver in his voice. The biggest moment of the night came with the ballad “Stay” — it was just him, an acoustic guitar and 17,000-odd people singing along. He gave fans a moment to recover, lit a cigarette, and went into his current hit, “Circles,” as he paced up and down the stage.

Nearing the end of the night, Post brought out Swae Lee (one of the support acts on the tour) for their Grammy-nominated tag-team track, “Sunflower,” while throwing out sunflowers into the pit. Before he closed out the show with “Congratulations,” he told the crowd: “Live your life, live your dream, live your truth — and don’t let anybody stop y’all, ‘cause each and every one of you are f—ing rockstars.” And after a night like that, it’s hard not to believe him.