Frank's bandmates, played by Maggie Gyllenhaal, François Civil, and Carla Azar, are used to Frank's quirks, but the new keyboard player Jon (Domhnall Gleeson) is a little freaked out by the whole thing. He's dying to know what Frank's face really looks like. They come up with a system where Frank explains what his face is doing under the head — smiling, blushing, looking pleased — but Jon can't resist trying to get to the bottom of what's going on beneath the mask. Jon sneaks into Frank's bedroom to investigate while Frank's in the shower, and he finds that Frank even showers with the damn thing on. Meanwhile, Frank's bandmates are equally put off by Jon, especially the temperamental thereminist Clara (Gyllenhaal). It's all coming to a head, if you will, especially once Jon gets them a gig at SXSW.
What's it like donning that crazy fiberglass head with its immutable, placid punim? A lot of fun, as you can see from Fassbender’s performance on The Colbert Report the other night.
"I found it really liberating," Fassbender said during a press conference with the film's cast and crew. "I was learning an accent, and I'm practicing like this," he intoned in Frank's flat Kansas cadence. "And, once you put the head on, there's a reverb thing that's going on in there. It kind of puts the hearing off a little bit, and it's hard to sort of locate some stuff, but that was it."
The inspiration for his character was Frank Sidebottom, the alter ego of the late Chris Sievey, a British musician who passed away in 2010. Cowriter Jon Ronson, a prolific journalist and author of books like The Psychopath Test: A Journey Through the Madness Industry and The Men Who Stare at Goats, played the keyboard in Frank Sidebottom's Oh Blimey Big Band in the '80s.
The major thing that Sievey's Frank and Fassbender's Frank have in common is the cheery, expressionless head, and that's about it. Ronson explained that Chris "didn't really want there to be a character based on [him] in the film." He added, "Chris didn't suffer from any mental illness."
Ronson drew inspiration from friends and other musicians, including Daniel Johnston and Captain Beefheart. It's no coincidence that Gleeson's character is a keyboardist named Jon, but that's pretty much where the similarities to real-life people begins and ends.
"As soon as I put the head on, it gave me an element of mischief. It gives the anarchic quality of Chris Sievey's original Frank Sidebottom character," Fassbender said. "For the other actors, it never mattered that I couldn't make eye contact really with other actors, because Frank is Frank, and Frank lives in his own universe, so I was hoping for them it would be the same. 'Is it listening? Is he not listening? Did he hear that?' They're used to him anyway."
Although Fassbender didn't quite take to the comparison between the scent inside Frank's head by the end of production and the shaggy muppets roaming Times Square, everyone seemed to agree that Frank's head is pretty personal.
"I think we would have to know you really well and like you a lot to put that head on," Gyllenhaal said with a straight face.
"And, we didn't," Gleeson added. "That tells you everything."
"It seemed like, really, there'd be a lot of you in there," Gyllenhaal observed.
"It's like wearing somebody else's underpants," Gleeson offered.
"It's like a beard that got out of control. There's crumbs in there. Pretty gross," Fassbender agreed.