Contrary to anything and anyone, Frank the character doesn't have much of a process, he is the prototype of the mad genius. A myth, more than a man. After all, he can write songs about anything. Really.
Based on Frank Sidebottom, Chris Sievey's comic persona, and inspired by Captain Beefheart and Daniel Johnston, Domhnall Gleeson, Maggie Gyllenhall are great, but Michael Fassbender is just incredible. For a guy who spends 90% of the movie wearing a fake head, he does a hell of a job.
The soundtrack is something. In particular "I Love You All", a song that ends the movie and makes me think of what Joy Division's Ian Curtis could have done if he ever played with The Beta Band. Amazing stuff.
Michael Fassbender cantando I Love You All en The Colbert Report 6 Agosto 2014 from Michael Fassbender Fan on Vimeo.
Stephen Rennicks whose responsibility of coming up with all these crazy ass tunes fell upon, gave a pretty interesting interview to LA Weekly. The whole process is messy, as Austin Kleon would put it.
Just go ahead and watch it, it's good stuff.