IF YOU haven’t heard of Glee, you must either be dead or you’ve been living in a cave for the last few years (possibly rocking gently with your fingers in your ears).

It’s a worldwide sensation whose relevant plot lines and pop culture references mixed with a heavy dose of musical theatre have accrued (or brainwashed depending on your opinion) thousands of fans and caused an insufferable amount of office discussion.

News Shopper: Glee cast perform live in Glee: The Concert Movie

Glee: The Concert Movie is something which only the hardest of hardcore Glee fans should see as it contains very little of the supposed charm of the show and will leave outsiders completely bemused.

That’s not to say if you’re completely unfamiliar with the series there’s nothing to enjoy – the singing is competent and the young cast is infectiously exuberant.

The choice of songs is as expected chosen from the pop songbook - Journey’s Don’t Stop Believing, Katy Perry’s Firework – and performed in a way which won’t cause uncontrollable aural bleeding (that is until the Barbara Streisand number threatens to rupture your ear drums).

For non-Gleeks (hideous word that it is) there’s a bonus as the movie is shorn of the prattling of its plot line as it launches directly into the songs without any preamble.

That’s a double-edged sword though as with absolutely no context for any of the songs, all you’re left with is 80-minutes of pop songs covered by a bunch of rictus-grinned teenagers.

Surely Glee is supposed to be about a bunch of social misfits (something which rings false even in the series)?

Without the contextual narrative for the show, Glee: The Concert Movie becomes nothing more than a shiny ode to consumerism and pop culture.

News Shopper: Glee cast perform live in concert

Worse, it’s interspersed with real-life “inspirational” stories about how Glee changed viewers’ lives including a dwarf cheerleader, a gay teen who gained the confidence to come out and a girl with Asperger’s.

Not that there’s anything wrong with these stories per se, but they’re delivered with such wide-eyed deer-in-headlights devotion and buckets of gushing schmaltz you begin to suspect they’ve been replaced by a cast of pod people.

There’s also something decidedly hard-sell about the seas of grinning faces – something almost evangelical, like robots which only have one setting, as if Glee is trying desperately to justify itself.

It’s like sitting in on a televangelist prayer meeting. Can you feel the pow-ah?!

Even fans of the series not put off by its insufferable preachiness will have their gripes. How come Will (Matthew Morrison) and Emma (Jayma Mays) are absent but Gwyneth Paltrow gets to make a warbling guest appearance?

The movie’s in 3D but aside from the occasional microphone in the face, it’s completely pointless, a cynical attempt to extract more money from moviegoers.

Non-Glee fans will probably hate it less than they expect but Gleeks themselves will be disappointed - which is shame because if you’re not a Glee fan, you’ve no business seeing this in the first place.

Glee: The Concert Movie (PG) is released on Friday.