The music playing throughout the Sixth & I Historic Synagogue in Washington just minutes before Tobias Jesso Jr. took the stage was somewhat indicative of an undeniable truth: Jesso is a walking paradox.

Upstairs, British songstress Adele crooned over a patiently seated crowd. Downstairs, indie stalwarts Modest Mouse eased flannel-clad drink buyers into the night’s show.

The songs are reminders that Jesso stands on a pedestal that has at least two diametrically opposed supports: On one side, there’s the relative anonymity that ushers him in with the indie likes of HAIM and ex-Girls member JR White. On the other, there’s the undeniable power pop sound that has garnered Twitter support from both Chloë Grace Moretz and Adele herself.

Tobias Jesso Jr.

The Canadian songwriter — “I’m a songwriter-slash-nothing,” he told the crowd — has one album, a couple of singles, and yet he’s already made a name much too large for the intimate performance he gave Tuesday night.

While his debut album, Goon, is cemented in the indie hall of fame by Pitchfork’s 8.5 rating and “Best New Music” anointment, he is also becoming something of a pop juggernaut, the names Joel and Lennon already being tossed around in comparison.

Luckily, he doesn’t seem to know what he is either.

He casually and humbly walked onstage after watching opener Okay Kaya’s entire soulful set. He even gave her a much-needed “You’re killin’ it!” as the Norway-bred up-and-comer bounced nervously through her beautifully melancholy “Clouds.”

“I’m calling this the farewell tour,” he announced. “Night two and I’m already wearing sweatpants.”

Tobias Jesso Jr.

Goofy and lovably self-deprecating, Jesso cracked jokes, mostly at his own expense, throughout the set. At 6 feet 7 inches with a mop of unruly brown hair, a sheepish smile and wide-with-wonder blue eyes, he seems more like an unkempt 18-year-old than a music-biz veteran of 29 who’s already had his fair share of successes and failures.

Until he starts singing.

Lanky frame hunched, teeth gritted and facial expression distorted, Jesso transformed while making his music. He blushingly introduced “Can We Still Be Friends” as the Cheers song (his mom thinks the two sound similar — and they kind of do) but after the first chord, he was all business, a songsmith and his craft, a poet and his pen, Lennon and a piano.

And so went the rest of the night.

“If I sound out of tune, [the piano] was tuned today, so don’t blame it,” he said. “Blame me.”

But there was little reason to worry; Jesso glided though the bluesy and subdued “Bad Words” and sweetly pining “True Love,” his gigantic hands never missing a note.

Oscillating effortlessly between his twin roles of unsure newbie (he would stop and ask “Does everything sound OK?”) and concentrating, tortured balladeer (the power vocals on his ’70s-sounding “How Could You Babe” probably could’ve shaken the synagogue down), Jesso won the evening with his warm personality as much as his musical prowess.

He’s a regular guy, but he’s not. He’s unsure, but he shouldn’t be. And that will get him places far beyond the cozy, anonymous venues in which he’s kicked off his tour.

After taking the time to sign autographs for practically 100 people (including one very jazzed Diamondback reporter), Jesso might not be able to sing about not having “no bestest friend until the end” because fans, both indie and otherwise, should be busting down his door relatively soon.