Start with a fiddle, a guitar and a stand-up bass. Add a suitcase drum and tin-can cymbals played by a former rock and zydeco drummer. Over that fine groove, hang Rani Arbo's expressive alto, seamless four-part harmonies, a splash of banjo and ukulele, and there you have it: the irresistible and unclassifiable band known as Rani Arbo & daisy mayhem. See them at the TPAC tonight.