By: Addison Wylie In the first Back to the Future film, Marty McFly straps on a guitar, turns to a baffled band, and says, “watch for the changes, and try to keep up, okay?”  With Coherence, filmmaker James Ward Byrkit is the rascally McFly, and I’m standing on the stage looking absolutely perplexed.  It’s because no matter how hard you try to keep up, Byrkit constantly has us on our toes.  Great Scott! Ironically enough,…