The hugely entertaining third – don't make it the last – episode in the world's best a cappella franchise defies any graded assessment such as that attempted by the star rating above. Pitch Perfect 3 doesn't make any effort at structure or coherence. Indeed, it turns its lack of interest in such things into a good self-regarding joke.

As so often with comic sequels, the characters, previously shuffled off to some neat denouement, need to be kicked back into disorder for the larks to begin. Anna Kendrick’s Becca, now a producer, is being misused by the musicians. Several of the other singers are behind on their rent. A reunion gig by rivals brings the Bellas mistakenly together. Then they end up on a tour with DJ Khaled. But these films only make sense if there’s a competition. Right? Out of nowhere it is announced that the band that performs best on the tour will be selected as Khaled’s next support act. “Phew! That was a lot of exposition,” somebody says.

It certainly was. But who cares? These pictures serve solely as a delivery system for the endlessly vibrant charm that results from the application of the Pitch Perfect formula. A boatload (literally, at one point) of enormously talented performers gets to flounce, pout, bond and, most importantly, warble their way through the most uncomplicated fun you will have in the cinema this Christmas. The comedy is mostly very cosy, but Rebel Wilson, as the proud "Fat Amy" (don't blame me), has been carefully positioned to inject shots of acid every five minutes or so. Their presence barely explained, John Michael Higgins and Elizabeth – top a cappella broadcasters – are also back with some delicious off-colour remarks. "Lost in a sea of seamen," Higgins remarks as the team perform with sailors.

Of course, it's also about the music. There's such juice and joy in these versions of 1980s hits. There's such energy in the subversion of cheese. The closing take on George Michael's Freedom! '90  is as good as any you'll hear.

And yet. This barely counts as a feature film. We are dumped into Pitch Perfect World and, after many barely connected scenes, propelled out of that world 90 minutes later. John Lithgow's scenes as Fat Amy's useless Australian dad could have been written, performed and shot in the time it takes to sing two choruses of Toxic.

Never mind. I’d watch Pitch Perfect 4 right now if I had the chance.