At New York Theatre Workshop, 'Once,' falling softly into a musical
NEW YORK -Â Anyone who caught the Irish guy Glen Hansard and the Czech girl Marketa Irglova playing their gorgeous song "Falling Softly" on the Academy Awards telecast has a sense of both the strength and fragility of "Once," the haunting, 2006 independent movie drawn from their unlikely story of love on the streets of Dublin. Even at the epicenter of bejeweled commercial hype, this pair seemed curiously untouche…