A marching band is a group in which instrumental musicians perform while marching, often for entertainment or competition. Instrumentation typically includes brass, woodwind, and percussion instruments. Most marching bands wear a uniform, often of a military style, that includes an associated school or organization's colors, name or symbol. Most high school marching bands, and some college marching bands, are accompanied by a color guard, a group of performers who add a visual interpretation to the music through the use of props, most often flags and rifles.
Marching bands are generally categorized by function, size, age, gender, instrumentation, marching style, and type of show they perform. In addition to traditional parade performances, many marching bands also perform field shows at sporting events and at marching band competitions. Increasingly, marching bands perform indoor concerts that implement many songs, traditions, and flair from outside performances.
Marching bands originated with traveling musicians who performed together at trade festivals and local celebrations throughout the ancient world. Such groups were also used by tribal rulers to display pageantry that could serve to enhance their power and influence, as well as impress visitors. Throughout history, these organizations evolved and became more structured within the armies of early city-states, becoming the basis for the military band, from which the modern marching band emerged. As musicians became less important in directing the movement of troops on the battlefield, bands moved into increasingly ceremonial roles within governments, communities, and educational institutions. However, many military traditions survive in modern marching bands. Those that march in formation are often ordered to "dress ranks" and "cover down files". They may be called to "attention", and given orders such as "about face", "forward march", and "halt". Uniforms of many marching bands developed directly from and often still resemble military uniforms.