Jon (Gleeson) is a wannabe musician, possibly talented but painfully uninspired, who crosses paths with the band Soronprfbs – that's not a spelling error, and it's pronounced exactly as it's spelt – just as their keyboardist is attempting to drown himself. Not seeing this as the warning it almost certainly is, Jon joins the band right before a gig, which ends violently within seconds of it starting. Looking for a return to creative surroundings, they head off to a remote cabin to record their new album in isolation. Oh, and the lead singer, Frank (Fassbender), is a potential genius and/or lunatic who never takes off his giant, papier-mache head.

In case you hadn't picked up on it yet, Frank - both the movie and the title character - is quite odd, and will absolutely not be to everyone's taste, and you'll either revel in the full-tilt bonkers tale, or find the weirdness quite alienating. Director Lenny Abrahamson has done a complete 180 from his previous film What Richard Did, as we're dumped into a world of bright colours, loud characters, and a situation just about as far removed for reality without being labelled sci-fi.

Gleeson is our way in; a man who dreams of more, and doesn't know what to do with it once it's presented to him. Fassbender, bringing another career defining performance even behind an emotionless mask, can't help but steal the movie out from under everyone. Headlining the band and willing to let creativity be all the riches he desires, he's filled to the brim musical and personality influences from the likes of David Bowie, Gorillaz, Radiohead and more, as well as actual inspiration from the likes of Daniel Johnston and Captain Beefheart.

The script, co-written by author Jon Ronson, does a good job of taking it's time with the story, developing the characters, and giving the supporting members of the band, including an incredibly acidic Maggie Gyllenhaal and adorably optimist Scoot McNairy, some fantastic moments together. Yet even as the laughs are coming, you know there's trouble ahead, and Frank trips when fame comes knocking for Soronprfbs and the band head to the SXSW festival. Whereas the rambling comedic nature of the film worked up to this point, the mistaken musical prophet angle gets worked to the bone here, and the movie suffers for it.

Despite this mis-step, Frank remains a hilarious quirky treat, and is quite unlike anything else you’ll see this year.