Jon (Domhnall Gleeson) spends his days living with his parents in a no mark small town tweeting his lunch to his 18 followers dreaming of a new life as a rock star. A chance encounter finds him living in a remote farmhouse in Ireland recording an album with the enigmatic Frank (Michael Fassbender) and his avant-garde band.

The first thing both Jon and the audience notice about Frank is his large giant fake head which he wears all the time. For those of you of a certain age like me you will recall a strange comedian who often turned up on children’s TV called Frank Sidebottom – and this is who Frank in the film looks like. For me this was very disconcerting at first as I always found Frank Sidebottom not only a bit unnerving but also pretty crap and unfunny. However, within 10 minutes of seeing Fassbender prancing about on screen singing and dancing and being very cool and sweet, I forgot about the original Frank (who was an inspiration for the film written by Jon Ronson who toured with Frank Sidebottom in the 80s) and instead fell pretty much in love with this one.

Frank’s gentle guru-like manner is offset by his band mate Clara (Maggie Gyllenhaal) who is the most hostile towards new keyboard player Jon and violently aggressive in her musical style. The other band members are suitably sullen and “crazy” as befits their personas as members of the eccentric Soronprfbs.

Jon’s tweets, blog entries and YouTube clips of his experience in the band makes it very current; it also appears to be a commentary of the unrealness of the online world, in stark contrast to the melting pot of humanity we see during the recording of Frank’s album.

By turns funny and touching this is an extraordinary film. The excellent casting of Fassbender means that you relate to Frank despite him being hidden behind the mask, perhaps even because he is hidden, and his unique view of the world.

This will make you laugh and cry and think, that’s pretty good for 94 minutes.

Read my interview with director Lenny Abrahamson here.