Personnel and Instrumentation

The size and composition of a marching band can vary greatly. Many bands have fewer than twenty members. Some have over 500. The Allen High School marching band, known as the Allen Escadrille, has nearly 600 members and is believed to be the largest in the world.A marching band is typically led by one or more drum majors, who are called field commanders in some ensembles.

They are also led by other student leaders that can include field lieutenants, and captains of other sections like brass, drumline, and woodwinds. The drum major often conducts the band, sometimes using a large baton or mace. In many school bands, the drum major is the student leader of the band, followed by students within the band that lead a section, squad, letter, row, etc. Bands may also be led by a more traditional conductor, especially during field shows, where a stationary conductor on a ladder or platform may be visible throughout the performance. Usually clapping or a whistle is used to issue commands.

American marching bands vary considerably in their exact instrumentation. Some bands omit some or all woodwinds, but it is not uncommon to see piccolos, flutes, clarinets, alto saxophones, and tenor saxophones. Bass clarinets, alto clarinets and baritone saxophones, bassoons and oboes are less common. Brass sections usually include trumpets or cornets, mellophones (instead of horns), B♭ tenor trombones, euphoniums or baritones, and sousaphones or tubas (often configured so that they can be carried over the shoulder with the bell facing forward). E♭ soprano cornets are sometimes used to supplement or replace the high woodwinds. Some especially large bands will use flugelhorns to cover the lower trumpet parts. Alto horns can also be used in place of the mellophone, although this is rare. Bass trombones are also sometimes used, especially in large bands.

Marching percussion (often referred to as the drumline or back battery) typically includes snare drums, tenor drums, bass drums, and cymbals. The glockenspiel, or "marching xylophone", is used by some ensembles. All of these instruments have been adapted for mobile, outdoor use.

For bands that include a front ensemble (also known as the "pit"), stationary instrumentation may include orchestral percussion such as timpani, wood blocks, marimbas, xylophones, vibraphones, chimes, as well as a multitude of auxiliary percussion equipment. Until the advent of the pit in the early 1980s, many of these instruments were actually carried on the field by marching percussionists. Some bands also include instruments such as synthesizers, electric guitars, and bass guitar. If double-reed or string instruments are used, they are usually placed here, but even this usage is very rare due to their relative fragility.

Instrumentation varies widely from band to band, so no generalization is completely correct. There are bands where members play string instruments, or bang on brake drums, empty propane tanks, and trashcans with drumsticks.

Large bands also require a number of support staff who can move equipment, repair instruments and uniforms, and manipulate props used in performances. In high school bands, these activities are usually performed by volunteers, typically parents of band members or the band members of the lower grades.