The Diverging Musical Paths of Selena Gomez and Miley Cyrus

Teen stardom is about being special: one kid’s talent and dreams standing in for millions. But the adult world affords fewer favors. How former child stars transition into adulthood has evolved over the decades, but there’s still no one true path to success.

Invariably, though, there’s a rupture, the moment in which the skin of youth is definitively molted. Of late, Miley Cyrus, 20, and Selena Gomez, who turned 21 on Monday, have each been pushing back in different ways — Ms. Gomez with her role in the film “Spring Breakers,” and Ms. Cyrus with her sometimes erratic, sometimes free-spirited tabloid life.

And yes, they are both still making music, though they’re using it for different things. For Ms. Gomez, who just released her debut solo album, “Stars Dance” (Hollywood), it’s a starchy place holder, a steppingstone from the naïve yesterday to the uncertain tomorrow. For Ms. Cyrus, whose single “We Can’t Stop” (RCA) is the No. 3 song in the country, it’s a rocket ship designed for maximum speed, the vehicle that can help her put her old life far in the rear.

“We Can’t Stop” is a low-key burner produced by Mike Will Made It, whose work expertly straddles urgent, dark R&B; hip-hop gravity; and pop accessibility. It’s a rejection of all of teen-pop’s brightness, except in the chipperness of the chorus, which basically amounts to Ms. Cyrus’s gloating about misbehaving.

“We Can’t Stop” is about youth, and the sense that it is best spent fast and irresponsibly. In the video, Ms. Cyrus pops a gold grill into her mouth, dresses like someone who shops at VFiles, makes out with a doll and, as has been her recent wont, gets to twerking, the derrière-centric stripper-derived dancing du jour.

It’s a statement of young-woman independence from someone choked in her own youth not only by Disney fame, but also by being the child of a celebrity. Plenty of former child stars rebel, but Ms. Cyrus is taking the express lane. “Everyone in line in the bathroom/trying to get a line in the bathroom,” she sings at one point, in an alluring, husky croak. Elsewhere she spits out a line that, depending how you hear it, says “dancing with Miley” or “dancing with molly” (as in Ecstasy).

Over the last year, Ms. Cyrus has become something of a TMZ fixture, not for Britney Spears-style meltdowns, but for feeling out new forms of rebellion, including the touristic appropriation of black culture she shows off in the song’s video. (That’s doubly hilarious given that after she referred to Jay Z in her 2009 breakout pop single “Party in the U.S.A.,” she insisted she’d never even heard a Jay Z song.) But give Ms. Cyrus credit for keeping her creative life and her public life consistent; the closer the two get, the better an artist she’s becoming.

Ms. Gomez is walking a lower wire on her album, though it’s unclear why. She’s already dispensed with her supposed teenage naïveté with her star turn in “Spring Breakers,” Harmony Korine’s teen apocalypse film (even if she was the most timid of all its stars).

But music still matters for Ms. Gomez, as it does for most of her Disney peers. It has a low barrier to entry and it has the greatest potential for viral spread. One good TV or film role might earn some credibility, but stumble upon a hit song, and you can live on forever.

Of all her Disney-generation peers, though, she’s been the least convincing musician. In their younger years, Ms. Cyrus was more talented than Ms. Gomez, though less intriguing. Their fellow ex-Disney star Demi Lovato, 20, has carved out similar routes with far more success; Ms. Lovato is twice the rebel Ms. Gomez is, and four times the singer.

Before “Stars Dance,” Ms. Gomez released a string of pleasant enough but undistinguished releases as part of Selena Gomez & the Scene. He solo album is safe, too, in its eclecticism, which is closest to the spirit of Gwen Stefani — breathy, wide-ranging, largely toothless.

This album bears scars of faceless modern club music, as on “Forget Forever” and “Write Your Name,” which includes a whisper-rap right out of Madonna’s “Vogue.” “B.E.A.T.” is dirtier and more promising, aiming for Kesha’s moistness but landing somewhere closer to no-hit-wonder Dev’s “Bass Down Low.” The producers of “Slow Down,” with its punk-funk backdrop, appear to have listened to a Gang of Four album, or at least one by the Rapture. There are also flickers of rocksteady on “Come & Get It,” and the brattiness of Icona Pop on the excellent “Birthday.”

Ms. Gomez has grown up, too, though she’s not as eager to show it off as Ms. Cyrus. On the banal “Undercover,” she sings, “Find me in the shadows, and pull the shades down until tomorrow.” (A similar awakening is had, to a much less tawdry degree, by the Nickelodeon star Ariana Grande on her recent single “The Way.”)

And “Love Will Remember” appears to close the chapter on Ms. Gomez’s relationship with Justin Bieber: “We lit the whole world up before we blew up/I still don’t know just how we screwed it up.”

A leaked version of the song included what appeared to be a love-proclaiming voice mail from Mr. Bieber. That version doesn’t appear on the finished album, but that it made its way out into the world didn’t feel accidental. Ms. Gomez’s real adulthood gambit might not be musical, or creative, but psychological.