Avril Lavigne has been a lot of things. You probably think of her most as the necktie-rocking, eyeliner-inked rebel who skated onto the scene in 2002 and shook up the Britney-dominated pop landscape. In 2007, after an emotionally intense second album, she injected a burst of bubblegum into her music, putting pink streaks in her hair and cluttering her aesthetic with skulls and hearts. In 2011, she emerged as a brooding, lullaby-singing romantic, and in 2014, she was gone. And so, when Lavigne returned last year after taking a long break from music to battle Lyme disease, the artist we'd known for almost two decades was, suddenly, a mystery. But not for long — her sixth album, released in February, introduced us to a self-proclaimed "warrior"; someone older, wiser, but still down to rock.

All of those distinct sides of Avril come out to play on the singer's Head Above Water tour, which kicked off last week and marks her first headlining trek in five years. At L.A.'s Greek Theatre on Wednesday night (September 18), she acknowledged that fact while encouraging the crowd to "lose yourself in the music and have the best time." That wasn't hard to do, because the next hour was a total hit parade — just two songs from Head Above Water made the setlist, beginning with the soldier-on title track, which opened the show in stunningly emotional style. From there, Lavigne flew through a career-spanning set of angsty jams ("My Happy Ending," "Don't Tell Me"), party-starters ("What the Hell," "Here's to Never Growing Up") and stirring ballads ("Keep Holding On," "When You're Gone").

The first curveball of the night came when Lavigne flexed her songwriting résumé by belting "Breakaway," a hit she wrote for Kelly Clarkson in 2004. A few minutes later, her band took over with an extended instrumental of "Hello Kitty," twisting the EDM-pop thumper into a hard-rock banger. And in another head-scratcher, Lavigne hopped behind the drums for a cover of Weezer's "Beverly Hills," with opening act Jagwar Twin taking lead vocals.

And of course, there was the song that started it all. "This next song is special to me because it was my first single ever, 17 years ago, when I was 17," Lavigne said, dedicating "Complicated" to her day one's while reminding us that she's been at this for half of her life. She busted out a goofy high kick before the final chorus, as the song's early-aughts video played on the big screen behind her. In it, she and her buddies perform at a skatepark and wreak havoc in a mall; a concept miles away from the cinematic, sweeping drama of "Head Above Water." Even so, Lavigne isn't an artist who scoffs at her older, less mature material; rather, she revels in it and celebrates it. She had a goddamn blast with "Girlfriend," dancing around the stage while singing, "Hell yeah, I'm the motherfucking princess" with the same gleeful brattiness she had 12 years ago.

"Sk8er Boi" ended the main set with a still-effective punch and a blast of confetti, but it was back to serious business for the two-song encore. Wearing a red-caped gown that made her look like a goth Little Red Riding Hood, Lavigne manned the piano for her most recent single, the melodramatic "I Fell In Love With the Devil." The 2002 power ballad "I'm With You" ended the show on a poignant note, with the big screen showing scenes from that video mixed with water imagery à la "Head Above Water"; a blending of old Avril and new Avril. Lavigne may have once vowed to never grow up, but she's certainly continued evolving, especially over the past few, transformative years. Thankfully, she hasn't left her old selves behind; the hit-packed show is a fun-loving celebration of her legacy. There's nothing complicated about it.