Corporal David Linnenkamp, a trombone player with Marine Corps Band New Orleans, rehearses at the Ponce La Perla Theater before a concert to celebrate the Marine Corps Reserve Centennial in Puerto Rico on Oct. 17, 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)