Master Gunnery Sergeant Robert L. Trenum is originally from Westernport, MD. He graduated from Westmar High School in 1995 and enlisted in the Marine Corps in September 1995. Upon completion of recruit training at Marine Corps Recruit Depot, Parris Island, SC, he attended the basic course of instruction at the Armed Forces School of Music.
His first fleet assignment was as a percussionist with the Marine Corps Air Ground Combat Center Band, Twentynine Palms, CA, where he served as administration chief, percussion section leader, fire team leader, and squad leader. He was promoted to corporal in December 1996 and sergeant in June 1998.
In September 1999, he was assigned to Drill Instructor School at Marine Corps Recruit Depot, San Diego, CA. After graduation, he was assigned to First Recruit Training Battalion, Alpha Company where he served as a drill instructor and senior drill instructor. He was later reassigned to Headquarters Company, First Recruit Training Battalion as the battalion S-4 chief and S-4 officer. In January 2002, he was promoted to staff sergeant. In December 2002, he attended the Marine Corps Martial Arts Instructors Course and earned his green belt in the Marine Corps Martial Arts Program (MCMAP).
In September of 2003, he detached the First Recruit Training Battalion and reported to the First Marine Division Band. His assignments within the division band included percussion section leader, rhythm section commander, training chief, supply chief, and assistant instrument repair technician. In 2004, while deployed with the First Marine Division Band in support of Operation Iraqi Freedom, he served as commander of the guard, sergeant of the guard, vehicle commander, and training senior non-commissioned officer in charge (SNCOIC) for the band. During this deployment, he earned his brown belt and his black belt in MCMAP. In 2005, he attended the Staff Noncommissioned Officers Academy Career Course followed by assignment as the Instrument Repair Technician and Supply SNCOIC for the division band.
In February 2007, he was selected for a lateral move to Instrument Repair Technician and attended Minnesota State College at Red Wing, MN, for training. He was promoted to gunnery sergeant in August 2007. In May 2008, he graduated from Redwing with high honors and a 4.0 GPA. In July 2008, he reported to the Marine Corps Air Ground Combat Center Band to serve as the unit’s Instrument Repair Technician. He attended the Staff Noncommissioned Officers Academy Advanced Course in April 2009. In July 2010, he transferred to Cherry Point, N.C., where he served as the 2d Marine Aircraft Wing Band’s Instrument Repair Technician.
In 2013, he transferred to Naval School of Music to serve as the head instrument repair technician for the field. He was promoted to master sergeant in February 2014 and to master gunnery sergeant in October 2018. He now serves as the Senior Enlisted Advisor for the Marine Detachment, Naval School of Music.
His military decorations include: Navy and Marine Corps Commendation Medal (three awards), the Navy and Marine Corps Achievement Medal (two awards), the Navy Unit Commendation (two awards), the Navy Meritorious Unit Commendation (two awards), the Marine Corps Good Conduct Medal (seven awards), the National Defense Service Medal (two awards), the Iraqi Campaign Medal (two awards), the Global War on Terrorism Service Medal, the Sea Service Deployment Ribbon, and the Marine Corps Drill Instructor Ribbon.