Shortly after taking the 9:30 Club stage on Thursday night, British soul singer Adele made a confession that didn’t feel quite right: “I’m really, really nervous!”

Really? Really? Based on her irrepressible giggles and torrential chitchat between songs, the 23-year-old seemed positively giddy. And for good reason. Her sophomore album, “21,” was enjoying its seventh week at the top of the American album charts, her heartsick hit “Rolling in the Deep” had just been named the No. 1 single, and here she was, kicking off her American tour before a capacity crowd that showered her with screams that felt almost Bieberian.

That meant that the energy in the room during Adele’s 90 minutes onstage had little to do with her music. This was a budding superstar and a lucky few of the adoring masses crammed into a relatively small club for some intimate face time.

Of course, most of the evening’s weird electricity was conducted by Adele’s towering, lightning-rod voice. Unlike so many of her soul forebears who sing as if they’re exorcising their lyrics, Adele seems completely comfortable in those superhuman lungs. “Should I give up? Or should I keep on chasing pavements?” she pleaded during “Chasing Pavements,” the 2008 hit in which her low-register verses bloom into beautiful anguish. It was a song about uncertainty sung with absolute certainty.

Meanwhile, Adele’s popularity is peaking at the intersection of two contemporary American obsessions: the acrobatic voices that haunt our television sets (“American Idol,” “The Voice,” “Glee”) and a recent national spasm of Anglophilia from which we’re still recovering.

“Did anyone watch the royal wedding?” she asked on Thursday, at which point the audience somehow figured out how to scream even louder. “How hungover was Harry? It was brilliant! I want to be best friends with Harry!”

The goofball banter was endearing, but chatter begets chatter. The crowd took it as a cue to talk among themselves, which sapped Adele’s already unsteady momentum of happy talk, sad song, happy talk, sad song . . .

“That was fun!” she declared after the sunny bounce of “Right as Rain,” one of too few up-tempo moments in the mix. “I don’t have many fun songs.”

Yep. She should do something about that. And even more vexing is her music’s bland timelessness. Most of it vaguely hovered between throwback R&B, vintage AM radio gold and ’80s power balladry worthy of yesteryear’s prom — all guilty-pleasure territories made somewhat more legitimate by her purposefully soulful oomph.

You want a singer with this colossal a voice to have a colossal vision to match. But despite her virtuoso turns, she didn’t do anything truly surprising up there. She’s like a superhero who only uses her powers to fetch cats from trees.

Still, she’s only 23. There’s still plenty of time for Adele to save the world.