In the last 18 months, the Swedish rapper Yung Lean — a child of the Internet made real — has evolved from suburban ennui to performance art to straight-up commodity.

The turning point came late last year, around the release of “Kyoto,” the first single from his forthcoming album, “Unknown Memory.” In the video, this dry, eccentric rapper drives an A.T.V., rides in a tiny boat and watches U.F.O.s, while rapping semi-nonsensical boasts over keening, spooky production: “S-A-D-B-O-Y-S/See me in the club with it tatted on my chest.”

Early Yung Lean was a fascinating curio. In one online video after the next, he stood awkwardly and rapped, gesticulating as if robotically reperforming what he’d seen in endless rap videos. The videos evolve over time, showing the path from a boy to something like a man. He looks at the camera more. His pose becomes more convincing. He ceases to be a commentator on the form and becomes a practitioner.

And, in fact, the small pit bull of a rapper onstage at the Marlin Room at Webster Hall on Wednesday night was a far cry from the awkward-looking kid in the “Ginseng Strip 2002” video. He was there for a pair of sold-out shows, his first in the United States.