Staff Sgt. Mark A. Pellon (left), 12th Marine Corps district musician placement director, and a guest saxophone player with Marine Corps Band New Orleans, and Master Sgt. Timothy Otis (right), Marine Corps recruiting command head musician procurement, and trumpet player, demonstrate a song while teaching a Master class on music to students attending the Conservatorio de Musica de Puerto Rico in San Juan, before kicking off the Marine Corps Reserve Centennial celebration concert on 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)