From last.fm:

Tilly and the Wall are an indie rock group which formed in Omaha, Nebraska, United States in 2001. The band consits of Derek Pressnall (vocals, guitar), his wife Jamie Pressnall (tap dancer), Neely Jenkins (vocals, bass), Kianna Alarid (vocals, recorder, bass) and Nick White (keyboards). The band has gained notoriety for having a tap dancer provide percussion instead of a drummer (although drums and drum machines are occasionally used on some of their recordings, and Pressnall is usually complemented by Alarid and Jenkins stomping on the floor). Read more about Tilly and the Wall on Last.fm.