The Dixie Chicks are among the artists participating in a five-month, 50-city bus tour to promote voter registration in advance of the Nov. 2 election, organizers announced Friday (June 4). The incentive is supported by Rock the Vote, a non-partisan, non-profit organization. Other tour participants include Alanis Morissette, Jason Mraz, Michelle Branch, the Donnas and Hoobastank. The tour will be a mix of concerts and appearances at college campuses and major political conventions. The extent of the Dixie Chicks' participation is not yet known. In fact, only three concerts have been confirmed -- all headlined by the Dave Matthews Band -- in Hershey, Pa., Bristow, Va., and Hartford, Conn. The bus tour includes a partnership between MTV and Rock the Vote as part of the network's Choose or Lose: 20 Million Loud initiative.