JoJo (Joanna Levesque) performs in front of a sold out crowd at the 9:30 Club. (Josh Sisk/The Washington Post)

JoJo is only 26 years old, but her musical career was almost over before it really started. After scoring TV time as a preternaturally talented singer at 7 years old, she signed a record deal at 12 and had a No. 1 pop song by 13, seemingly ready to pick up the big-voiced teen pop baton from recently “Stripped” Christina Aguilera. And then, nothing: JoJo (born Joanna Levesque) spent nearly a decade locked in a battle with her record label that prevented her from releasing new music.

Thankfully, the singer prevailed and avoided becoming a casualty of the music business, forced to spend her prime as music trivia. Last year, she released “Mad Love,” a triumphant album that found both her pop-R&B songwriting and impressive, four-octave vocal range intact. That vocal range was the main attraction on Tuesday night at the 9:30 Club as JoJo — flanked by a three-piece band and a pair of backup singers — sang her way through “Mad Love” and a handful of fan favorites from her teenage days.

JoJo’s melismatic riffs and runs were as impressive — and her upper register as clear — as ever, but the young veteran knows how to protect herself and her voice, especially after a bout of laryngitis forced her to reschedule seven shows earlier this tour. She knew when to step back and share the spotlight with the audience and her more-than-capable backup singers, but for every note she skipped, she hit three more, leaving only the most dedicated fans able to hear the difference.

Not that anyone at the sold-out venue cared about a missing note here or there. They were there for JoJo and her songbook, which is full of familiar tales of love gone wrong with partners who cheat, who won’t commit, who do too little too late. They grew up with some of these songs (“Baby It’s You” is so old that it references MTV) and the ones written when she was a teen have only gotten stronger with age; there’s scar tissue on all those broken hearts. For both JoJo and her fans, “Leave (Get Out)” isn’t the same song it was in 2004, and the rock-heavy remix she performed live seems to acknowledge that.

Midway through the show, JoJo slowed things down, sitting on stage to sing “Music,” the piano ballad that details how she used music to survive a childhood marked by her parents’ addictions — personal lyrics that some in the crowd decided to talk over. After a little shame-shushing, the audience tuned in for a message that might as well be about them: “Tell me who, who would I be without you? No matter how much we lose, every time, I bet my life on you.” After years in the wilderness, JoJo bet that her fans would still be there, and they are.