When the a cappella-themed comedy “Pitch Perfect” debuted in 2012, its success proved that audiences were hungry for the style of raucous yet decidedly feminine humor it served up. The inventive musical numbers didn’t hurt, either, and suddenly, the niche singing style most often seen on college campuses went mainstream.

With “Pitch Perfect 2,” the franchise went bigger and broader, to mixed results.

Now comes “Pitch Perfect 3,” which segues to action-adventure and leans so far into the weird that it’s strange, yet sometimes amusing. At least the music’s fun.

The film, written by Kay Cannon and Mike White, directed by “Step Up All In” director Trish Sie, follows the Bellas (formerly of Barden University) as they struggle with life after college. No longer able to perform regularly with their best friends, they’re creatively stymied and nostalgic for their collegiate prime. For one last hurrah, they decide to hop on a USO tour, which bizarrely takes place in Spain, Greece and the South of France — not Fallujah.

The formulaic tics of the franchise are present and accounted for. “Is there a competition? There always has to be a competition,” a manic Chloe (Brittany Snow) breathlessly asks. Of course there is (she just said that there always has to be a competition). On the tour, which is inexplicably sponsored by DJ Khaled (playing himself), four groups will compete to open for him on the last night. The Bellas are feeling insecure when they check out their competition. They find their rivals in the all-girl rock group Evermoist, headed up by a perfectly smarmy Calamity (Ruby Rose).

And yet, a competition just isn’t enough. Adding to the drama are some serious daddy issues. Amy’s (Rebel Wilson) long-lost father (John Lithgow) turns up for reconciliation, but he’s got more nefarious ulterior motives, and the girls have to put their special aca-skills to work to thwart him. It’s probably the only spy movie that will involve a choreographed performance of Britney Spears’ “Toxic” deployed as a diversion tactic.

“Pitch Perfect 3” is so breezy it’s completely weightless, but it manages to deliver just enough of the goods.