Trace Adkins will join a cast of actors and singers at the 16th annual National Memorial Day Concert to air live May 29 on PBS. The concert honors Americans who have served in the military, but this year's show also marks the 60th anniversary of the Battle of Iwo Jima. Other participants include Gary Sinise, Joe Mantegna, Charles Durning and Colin Powell. More than 300,000 spectators are expected at the event on the west lawn of the U.S. Capitol. The concert will also be broadcast on the Armed Forces Radio and Television Service.