It is slightly bizarre to listen to someone find her voice without having any idea what she's actually saying, but such is the experience for many of Juana Molina's listeners. And really, "slightly bizarre" is the name of the Argentine singer-songwriter's game. Molina frequently takes odd bends while remaining seemingly innocuous and soothing. And so Son is like the aural equivalent of Robert Altman's 3 Women: It's steadfastly weird but never ostentatious, the rare combination of eccentric and the real deal. Molina, who led a popular sketch-comedy television series in her homeland years before taking this niche musical turn, has lost nothing in timing. Whenever she runs the risk of plucking herself into singer-songwriter somnambulism, she senses it and comes to with a brand-new melody, a burst of field sounds or high-pitch gibberish.