As good a movie as Roman Polanski’s “The Pianist” is, it fails in representing the music, writes David Patrick Stearns. “How could anybody emerge from five horrific years of hard labor and starvation in World War II Warsaw with such clean, crisp, emotionally unclouded renditions of Chopin?” The answer? They couldn’t, and the real-life Wladyslaw Szpilman, whose memoir was the basis of the film, was profoundly changed, and with it his performances. “Such performances gain impact because the music’s lack of specificity allows it to be invaded by meaning in unpremeditated ways. Popular music, in contrast, has a verbal element that can serve as a political rallying point, but one that can render the music obsolete.”