Portland’s Time Based Art Festival brings performers from all over the world for 10 days of performances, exhibitions, music and movement. This year the Portland-based musician Erika M. Anderson, who has performed internationally under the name EMA, will present a piece of music, video and storytelling that she hopes will be like nothing audiences have seen before. We talk to Anderson about the piece and about the arc of her career from fronting punk bands in Montana to touring giant stadiums to returning to experimental noise.