From Vincent Van Gogh onward to Robin Williams, there is a fallacy in culture that all geniuses must suffer. Whether through addiction or mental illness, legions of fans think their favorite artist is great specifically because of the problems that befall him or her. Frank, the new comedy about a brilliant eccentric musician, is an angry retort to this misguided idea. It starts as a pleasant screwball comedy, only to view its subject with pity and sadness. Working from a screenplay by Jon Ronson and Peter Straughan, director Lenny Abrahamson successfully disabuses the audience from this cruel notion.