epa02627006 US musicians David Crosby (R) and Graham Nash (L) perform at a benefit concert in Tucson, USA, on 10 March 2011, to honor those in the wake of the shooting, which killed six people and wounded 13 others, including Democratic US Representative Gabrielle Giffords, on 08 January 2011. The funds raised will go to a new community foundation to promote civility, respect and understanding. EPA/GARY WILLIAMS