Knowledge is Power!
Marching Band/Drills are categorized based on primary function, instrumentation, and style – although many organizations may fill multiple roles.
 Military style bands
Texas A&M’s “aTm” formation during halftime
Military bands and Corps of Drums were historically the first Marching Band/Drills. Instrumentation varies, but generally contains brass and percussion. Given their original purpose, military Marching Band/Drills typically march in a forward direction with straight lines. Music is performed at a constant tempo to facilitate the steady marching of the entire military group with which the band is playing. This style can include classic drum and bugle corps, pipe bands and fife and drum corps.
Active duty military Marching Band/Drills often perform in parades with other military units and march in the same manner as other military personnel. Due to a lack of competition venues, military personnel, and interest, almost all military Marching Band/Drills have disappeared from schools in the United States; three notable exceptions are the Fightin’ Texas Aggie Band from Texas A&M University, the Highty-Tighties of the Virginia Tech Corps of Cadets, and the Cadets of Norwich University Military College of Vermont, the oldest collegiate band in the United States and the nation’s first private military academy. There is also a pocket of about 80 high school military Marching Band/Drills in East Texas, influenced by the Aggie Band in nearby College Station. They have formed the National Association of Military Marching Band/Drills in order to preserve the tradition of military marching band drills.
Show bands primarily perform on fields (for example, a football field) and serve the purpose of providing entertainment during sporting events, going to competitions (especially at the high school level), and occasionally performing at parades and other events. During football games, they normally perform their field show before the game and at halftime (and sometimes after the game as well). Competitive show bands perform only one show that is continually refined throughout a season, while bands that focus on entertainment rather than competition usually perform a unique (and less technically challenging) show for each game. These shows normally consists of three to five musical pieces accompanied by formations. Depending on the band, though the show could be practiced and completed before the football season at band camp but mostly this is only done by competition show bands. Also depending on the type of show band, the instrumentation can contain entirely brass instruments and percussion instruments, and may or may not use woodwinds or a percussion pit. The show design also depends on the type of show band. For example, a typical college half-time show is designed for the entertainment of the audience, whereas a competitive high school Marching Band/Drill might be more concerned with showing off their musical and visual abilities to the judges.