Australian singer and songwriter Sia performs at the Democratic National Committee LGBT Gala at Gotham Hall on June 17 in New York. (Mandel Ngan/AFP/Getty Images)

In the recent coverage of Australian singer Sia, the oddball chanteuse turned hired-gun hitmaker turned reluctant pop star, this is what no one has talked about: Many of the songs she writes for other people — the ones that made her more famous as a songwriter than she ever was as an artist — aren’t very good.

Sia doesn’t write career-changing masterworks of the “Someone Like You” or “Firework” or “Since U Been Gone” variety, at least not yet. She specializes in hyper-melodic, serviceable songs for foundering divas hoping to arrest their downward slide (Christina Aguilera’s “You Lost Me,” Britney Spears’s “Perfume”) or songs that serve as placeholders in between a superstar’s more memorable hits (Beyoncé’s “Pretty Hurts,” Rihanna’s “Diamonds”).

Two of the biggest hits she has written, David Guetta’s “Titanium” and Flo Rida’s “Wild Ones,” are songs on which she also sings. Sia’s songs work best when Sia is on them. Her new album, “1000 Forms of Fear,” her first in four years and first since she became a sought-after diva whisperer, is repetitive and formulaic and fraught. But the worst song on it is (mostly) better than the best song Sia ever wrote for somebody else. (Except for the sweet, dumb “Wild Ones,” a Guilty Pleasure Hall of Famer.) In the buildup to the album’s release, Sia gave interviews breaking down her rules of hitmaking. They include:

1. Arrange a song around an easy-to-grasp metaphor (“diamonds are shiny”).

2. Song protagonists should travel an inspirational, Oprah­esque path from “victim to victory.” (These are songs meant for pop princesses, not the National.)

3. No depressing choruses (see above).

4. Songwriting need not take all day. (Sia told the New York Times that it took her 14 minutes to write “Diamonds.”)

This was a rare lifting of the veil, a violation of the fourth wall that made Sia appear cynical (she’s supposed to be closer in spirit to a mysterious indie cool girl like Grimes than a mustache-twirling cultural despoiler like Dr. Luke) and wrongheaded at the same time: “1000 Forms of Fear” is strongest when it breaks its own rules.

It’s a feast of melody, stick-in-your-head choruses and grimly determined hooks, all delivered with the remorseless air of a military campaign. The songs are seemingly reverse-engineered from a list of things Sia thought you might like: downbeat lyrics about addiction (Sia has been open about her struggles with alcohol and pills) and bad love combined with giddy beats that are ladled over the top so you don’t notice the sadness. Meanwhile, the rubbery vocals twist and stutter and crack like eggshells. Sia, 38, began her career as a quirky singer-songwriter of restless appetites, but her years in the Top 40 killing fields have smoothed her rough edges. Her voice, once a genuinely weird natural wonder, is now suspiciously whimsical. It seems to fracture on cue.

“Chandelier,” the disc’s opening track and breakout single, is a stadium-size pop song with a deceptively dark chorus and vocals that evoke Rihanna, right down to the non­specific island accent. Companion ballad “Big Girls Cry” is another song about a depressive party girl, a Sia sub­specialty, that jackhammers its message when a chisel might do. (“I don’t care if I don’t look pretty/Big girls cry when their hearts are breaking.”)

“Cellophane” is a hiccupy ballad that employs every Sia-ism at once: Rihanna-lite vocals, minus the flat affect, lyrics that disarm (“Look at me/I’m such a basket case/While I fall apart, you’ll hide all my pills again”), and crinkling-cellophane sound effects for anybody who found the cellophane-is-fragile-like-me metaphor too subtle.

“Free the Animal,” an amelodic, jittery electro-pop curio that distantly recalls Nine Inch Nails’ “Closer,” is the year’s most unappetizing love song (“Kill me like an animal/Decapitate me/Hit me like a baseball”). Power ballad “Fire Meet Gasoline” trafficks in similar emotional savagery (“It’s a bad death/Certain death/But I want what I want”), but its hook is better. On an album full of contenders, it’s the likeliest heir to “Chandelier,” which is already (deservedly) her greatest hit.

For Sia, that might be a problem. She’s been vocal in her distaste for — and fear of — pop stardom. She performs with her back to audiences, won’t do photo shoots and, during a recent performance on “Late Night With Seth Meyers,” hid her face in a pillow while Lena Dunham danced in her place, wearing a Sia wig.

There are lots of ways to avoid pop stardom if you really don’t want it, and none of them involve making an album full of potential smash hits, discussing that album with the New York Times and performing those hits on national television. Sia’s come here/go away ritualized dance with fame can seem a little twee. On an album of calculatedly mammoth pop songs overlaid with a thin veneer of precisely calibrated eccentricity, her avoidance and embrace of the pop-music machine begins to feel like the same thing.

Stewart is a freelance writer.