Anyone at turns curious, enlivened and annoyed by the ubiquitous performers who populate New York City's subway stations would benefit from checking out Downtown Locals, a painstaking collection of the most passionate members from that assemblage. Filmmakers Robin and Rory Muir wisely choose to follow artists destined to struggle for the spare dollar, rather than the accepted members of above ground society who bring their craft to the stations just for kicks. Among the more amusing characters: Two “Mercury Men” intent on earning their right to continue their statuesque routine, even as the city refuses to recognize them as certifiable entertainers; a lonesome Columbian immigrant with the unlikely ability to tango with dolls; a guitar-strumming heroin addict and his youthful disciple. The narrative is situated around annual auditions in Grand Central Station for MTA's Music Under New York. Most of the film's subjects can't make the cut because their shtick isn't mainstream; over time, this starts to sound a helluva lot like ethnic cleansing. Downtown Locals screens September 15 at Williamsburg's Automotive High School as part of the Rooftop Film Festival. Seeing it is practically a civic duty for the commuting New Yorker.