It helps that Vienna's sound has never stood still. Her warm, delicate mezzo has drawn listeners since 2002, when her debut Waking Hour landed appearances on NPR's Weekend Edition, The Late Show with David Letterman, and the top of Amazon’s charts. But she’s built different worlds around that voice from album to album: the string-laced intimacy of Warm Strangers , the hushed jazz of Dreaming Through the Noise , the eclectically ambitious Inland Territory , the shimmering electronica of Aims .