Kid Cudi   (Photo: Pamela Littky)

Who would you rather listen to, a dramatist or a self-dramatist? The latter is increasingly easy to find, especially now that pop music has managed to combine two of its most appealingly self-involved modes: the bluster and braggadocio of hip-hop and the sulky confessionalism that runs through hip rock. Whether that mixture represents the best of both worlds or the worst of them is a matter of ongoing debate.

Either way, this is where Kid Cudi comes in. The 26-year-old swings wildly between vulnerability and bravado, rapping and singing in a blasé, mildly bitter voice. His first hit, 2008’s “Day ’N’ Nite,” was an elegy to the “lonely stoner”; 2009’s “Pursuit of Happiness” mixed lines about night terrors with big talk about living like a drunk driver. The tracks sounded wounded and pent-up, which is always a tense combination when you come across it in real-life guys. Those songs were included on his debut LP Man on the Moon: The End of Day, and when the album shot up to Billboard 200’s top five, we waited to see how that tension mixed with fame.

One answer came this summer, when Kid Cudi was arrested for cocaine possession after he allegedly smashed a woman’s phone and broke down a door (the charges will be dropped if he stays out of trouble for six months). That’s no huge surprise: These days, even nice-guy crooner Bruno Mars has a coke arrest on his record. What was amazing was how readily the music world treated the incident as just another dramatic arc in Cudi’s story, as if the person on the other side of the door might have been an extra. Cudi went on to say he’d taken cocaine to get through long days of tough interviews, an explanation that combines his two main poses: It leaves him sounding vulnerable about a drug he used to keep up his bravado. Vulnerability and bravado are another tricky combination.

You can hear it in his new record, Man on the Moon II: The Legend of Mr. Rager, a weary and sometimes beautiful catalogue of trying times and overindulgence. The first track promises “some Generation-X shit,” and what follows does indeed include the kind of self-examination that used to get rock bands labeled “whiny.” The single, “Erase Me,” actually sounds like nineties alt-rock (Cudi’s currently learning guitar) and has the same ironic sneer; it’s about a woman who hates Cudi but can’t seem to avoid him.

It’s not sad-sack stuff; this is how a lot of stars swagger now. They’re worried, self-lacerating, and self-dramatizing, but they make it sound tough and cool. Cudi isn’t interested in the composure and self-control of other hip-hop stars—not in his behavior or what he feels like telling us about that behavior. He’ll do as he pleases, then we’ll listen to him grumble and marvel at how tumultuous life ends up. Trite as it is to point out, these are the same pulling-back-the-curtain qualities people love in oversharing memoirs and blogs: There’s something specifically modern about it. It’s why people complain that we’re all becoming narcissists or make the same jokes about the (alleged) self-indulgences of, say, Kanye West albums and Emily Gould essays.

But pop trades in personal connections, and guys who come on as strong as Cudi bulldoze their way into making them. Another payoff comes in the music he pulls together, a melodic take on hip-hop that feels woozy and genuinely passionate, inviting you as deeply into his head as the lyrics. One of Mr. Rager’s most striking tracks, “Ghost!,” has Cudi moaning miserably about how things will eventually make sense—there’s a comforting pull to it, like company in a dark pit. But vulnerability loses its power when it’s calculated to sound dramatic and masculine—when being wounded is another way of sounding hard. The bluster can feel bitter, paranoid, or mean. The less successful parts of Mr. Rager are like going to a party with a bad friend: The D.J.’s pretty good, but this guy just won’t stop bragging about the rough year he’s having.