Rebel Wilson’s avert-your-eyes new comedy “Girl Group,” which had its world premiere at the Toronto International Film Festival, gives you new appreciation for the artistry that went into “Pitch Perfect.”

It’s almost rude to compare the two — “Pitch Perfect” is a clever and lively romp while “Girl Group”’s a real stinker.

But given their mutual presence of Wilson, who also writes and directs this mangled mess, and the recycled story of young female underdogs trying to win a singing contest, a face-off is unavoidable.

Or perhaps my mind wandered so much to “Pitch Perfect” while watching the new movie purely as a coping mechanism for the cinematic trauma I was enduring. Who’s to say?

The chief difference is that this time Wilson gets promoted from wacky sidekick Fat Amy to the main event, except her schtick stays exactly the same. You can probably hear the Aussie’s dry and detached but blunt deliveries in your head as you read a subpar joke such as, “When I saw you, I thought: ‘a bunch of reject Pokemon.’”

Wilson’s recognizable style is funny when used to break up a dramatic confrontation or lighten up an emotional moment, as in “Bridesmaids.” However, the actress is deathly allergic to vulnerability. There is not one honest second in “Girl Group.” So what we get instead is a mashup of cheap gags, empty empowerment and songs you pray will end.

Wilson plays Tassie, the former member of a UK Spice Girls-ish pop group called, ugh, Gurlfriends. They met in school in 1997, got discovered and skyrocketed to superstardom with the single “Summer Snog.” It gets worse and worse.

There are a handful of original tunes sprinkled in here alongside hits like Destiny’s Child’s “Survivor” and Chappell Roan’s “Hot To Go,” none of which are top-drawer. Believable new music is what makes comedies like “This Is Spinal Tap,” “Best in Show” and even “Josie and the Pussycats” work, even though they’re affectionately mocking bands. “Girl Group” did not get the memo.

In the aughts, Tassie earns a hard-to-shake reputation for misbehavior — scarfing down booze, popping pills and getting DUIs. Twenty years later, the fed-up other members (which include Mel C. from the Spice Girls — oh, how the spicy have fallen) ask her not to join them on their worldwide reunion tour.

They decide to replace her with a diva singer played by Nicole Scherzinger, who’s mostly here to twerk.

After yet another car accident, Tassie is forced to work community service, which translates to unhappily mentoring a quintet of misfit girls who like to sing together. So, now there’s some “Sister Act 2” in the mix.

The thing is, the friends are already pretty good from the beginning. The first song they sing for Tassie is quite pretty. They’re a little nerdy, sure, and one is too loud, but they’re hardly hopeless.

We’re not especially convinced that Wilson needs to teach them how to be stars, however we’re dead certain she needed to rewrite her script to have some actual characters in it.

This isn’t like “The House Bunny,” in which each outcast of the sorority had a distinct and forceful personality. Everybody here is an inoffensive clone. I got a sense that Wilson wasn’t willing to let other cast members be funnier than her. That includes, sinfully, the underused Jennifer Coolidge as Tassie’s manager.

The movie is about more than just training them up to boost their self-esteem and learn a lesson. Tassie hears about a competition to find the next great girl group and, desperate for cash, signs them up. I was rather skeptical of this battle, as there are hardly any pop girl bands of this kind left. It’s like trying to find the next great stegosaurus.

All the usual tropes of this genre are alive and unwell. The ladies’ have mostly blonde rival competitors whose only other noticeable trait is that they take aerobics classes.

And one of the moms, a restaurant worker, vocally disapproves of her daughter wasting her valuable time on music.

“No! You are too smart for singing!,” she really says in the year of our Lord 2026.

Pretty much all the blame for this pitchy movie falls on Wilson. The writing, which can’t even effectively rip off films that have been made hundreds of times, puts the rough in rough draft, of course. But her cut-corners direction is just as big a calamity. There are stagey scenes of, say, the scrappy crew walking into a hallway from a room where you can almost hear Wilson yelling “action!”

And the big show at the end, even with its concert lighting and rainfall effect, is edited in a metronomic way that puts us to sleep instead of perking us up.

Spice up your life? Spice up your movie!