During World War I, soldiers carried song books in their kit bags. In World War II, some soldiers had access to radios and could hear Glenn Miller and the Army-Air Force Band perform. Others were lucky enough to catch Bob Hope headline a USO show. During the Korean War the military set up its own radio network, Armed Forces Radio (Korea). Vietnam had all these outlets and more. Its GIs brought their own radios and instruments from home. They bought records and swapped tapes of their favorite music.