Marines with Marine Corps Band New Orleans join students from the Conservatorio de Musica de Puerto Rico in San Juan to rehearse for the Marine Forces Reserve Centennial Concert Oct. 18, 2016. The Marine Corps Reserve is commemorating 100 years of rich history, heritage, espirit-de-corps, and a bond with Puerto Rico and communities across the U.S. The celebration recognizes the Reserve's essential role as a crisis response force and expeditionary force in readiness, constantly preparing to augment the active component. (U.S. Marine photo by Sgt. Sara Graham/Released)