Breakout band Snail Mail, fronted by Lindsey Jordan, performed a sold-out show at the Black Cat. (Josh Sisk/for The Washington Post)

The past couple of months have been pretty good for Lindsey Jordan: major profiles in the New York Times and The Washington Post, a passing-of-the-torch interview with Liz Phair on a very high-profile worldwide music website, and a cresting wave of thinkpieces and online buzz strong enough to suffocate anyone caught in the undertow. All this, we’re constantly reminded, as the girl from Baltimore hits the ripe old age of 19.

It was impossible to tell how many of those who packed into the sold-out Black Cat on Tuesday night — a mix of under-21s, bespectacled male indie rock geeks and a smattering of those who turned 19 a long time ago — were there to see what all the fuss was about or just to bask in Jordan’s starkly confessional indie rock songs.

Remarkably, Jordan, who records and performs under the moniker Snail Mail, has only released one full-length album, and that record, “Lush,” came out just six days ago.

Snail Mail was a standard rock four-piece for Tuesday night’s show, but Jordan’s singing, guitar playing and hair-tossing, slyly smiling presence was clearly the main attraction.

The 10 spiraling, enchanting songs that make up “Lush” — and most of their only other release, the 2016 EP “Habit” — are best experienced in singular listening situations: on headphones, alone in the car or, like the environment in which they were composed, alone in the bedroom, long after dark.

(Josh Sisk/for The Washington Post)

(Josh Sisk/for The Washington Post)

Onstage in front of a sellout crowd, those songs felt different. Jordan and the band seemed caught between the urge to feed off the crowd’s energy and rock them up, and the need to caress the subtle dynamics. Predictably, they didn’t really do much of either, often settling into a numbing midtempo clang.

There were moments when Jordan’s galvanizing stage presence, the band’s rickety indie sound and the songs all came together, though: “Pristine,” the first single from “Lush,” swept along in a heady, singalong rush; “Heat Wave” became an aching lament with its teetering twin guitars perfectly capturing the ennui of the lyrics; a solo version of “Anytime,” with Jordan accompanying herself on electric guitar, was starkly beautiful.

Snail Mail has played the Black Cat numerous times before, but never as an act with the power to sell out the club’s main stage. And while there were moments when it felt like watching the winner of a high school battle of the bands, there were others when it was possible to believe there is something to all the hype, that Jordan’s talent really might be exceptional and that she could emerge as a true beacon on the endless sea of chiming indie rock bands.

Either way, it seems Jordan and her Snail Mail is committed to growing up in public and that she won’t back down from writing songs about how it all feels. Listening along should be fascinating.