The rattle and roar of Chicago’s Lake Street ‘L’ is constant. It drowns out the words of Brian Andreotti and Bill Schopf, two of the principals with specialty film start-up Music Box Films. Inside a second-floor office adjacent to a modern art gallery, located in an industrial stretch of West Loop Chicago, Music Box Films performs its business behind a low-rise brick building without notice. For the four-month old distributor responsible for the surprise art-house hit of the summer, the lack of attention does not seem fair.