Michael Fassbender is hilarious. He displayed a bit of his comedic timing with the help of Quentin Tarantino's snappy dialogue in Inglourious Basterds, but until now he hasn't had a role that uses his ample talents in a truly funny way.

Enter Frank, a dark comedy about a young musician named Jon (Domhnall Gleeson) who finds unexpected inspiration in a band fronted by a man who wears a massive papier-mâché head. That is the titular Frank, played by Fassbender, and he's so far beyond eccentric that he almost loops back around to normal. He never takes the head off, even to shower, although he's always got a backup nearby in a box. He's obsessed with perfection and his vision for his band Soronprfbs (an unpronounceable word), the members of which all look up to him as a unimpeachable wizard, almost a benign cult leader. And while he's temperamental and prone to hysteria, he can sweet-talk strangers at the drop of a hat.

Jon finds his way into the band through a series of unexpected events, and despite unwarranted hubris he quickly realizes that his own musical abilities can't touch what Frank brings to the table. As the band holes up in a cabin to record their first album, he comes to view Frank with the same awe as the rest of Soronprfbs (including a delightfully aggressive Maggie Gyllenhaal and the perennially underrated Scoot McNairy as their manager). Jon compensates for his insecurities by documenting the band's progress on Twitter and YouTube, but when they develop a small following he sees an opportunity to capitalize on Frank's talents.

It's at this point where a moment of tragedy strikes and Frank becomes a bit of a road movie about the intersection between creativity and mental illness, especially in our modern world. This is a welcome change of pace but also a slightly forced one; it doesn't feel organic, more of a "this well is dry, so let's send our characters elsewhere." But it does help bring the themes to light; while the concept of the film is patently absurd, Frank isn't wearing the head for laughs, or even attention. He's a profoundly disturbed individual, and his interactions with the world outside of the cabin illustrate his inabilities to function in the circles he'd not-so-secretly like to be a part of.

Frank incorporates social media and the Internet better than almost any other film that touches on the subject. Even the savviest actors can sound moronic when asked to rattle off lines about tweets and Facebook likes, but screenwriters Jon Ronson and Peter Straughan have the almost unheard-of ability to illuminate via dialogue how social media impacts both the monotony of modern life and the quick rise to fame in this day and age. The person with the Twitter account or the YouTube channel doesn't change; it's how he (or she) is perceived that matters. Nonsensical hashtags and inane video clips can suddenly appear brilliant when the sharer has amassed a couple thousand followers.

They also do an excellent job of demonstrating why Frank would draw that kind of attention; his visual appeal is obvious, and while his compulsive musical tinkering may not have an end game, it's still magnetic in its comprehensiveness. Fassbender brings the perfect mix of Midwestern awkwardness (Frank is from Kansas) and insecure brilliance to the role; the head obscures his face entirely, but that only makes his muffled comments and expressive body language that much more hilarious. Whether it's describing his current facial expression to help whoever he's conversing with or moaning in fear when events aren't going his way, Fassbender's commitment to Frank's commitment is awe-inspiring. The 37-year-old may already be a phenomenon, but you can't grasp what he's fully capable of without seeing this film.

The lesson in Frank is to understand who you are; it's good to look beyond your comfort zone, but not so far that you lose your way. And even though achieving fame and glory seems easier than ever these days, some people just aren't destined for such things. Refusing to accept your limitations, or trying to circumvent them, is a sure-fire way to drive away those who love you for who you are.