As of 2014, the U.S. Department of Defense is the largest employer of musicians in the United States, with more than 6,000 musicians serving in active-duty, reserve, and National Guard bands. From its dual origins with drums and fifes in infantry units (foot soldiers) and trumpets in the cavalry (horse-mounted troops), music has served crucial roles in the U.S. military from pre-Revolutionary War times. With field musicians providing signals in battle and camp and band musicians entertaining, motivating, and serving in military ceremonies, reviews, concerts, guard mountings, drills, parades, and on the march, these musicians have learned their skills in a variety of ways. This article looks at military music in general and the tradition in the United States and examines methods of musical training.