A marching band instrument is an instrument that is used in a marching band. The four letter solutions for the term marching band instrument are Fife, TUBA, DRUM, and FLUTE. A Fife is a small, high-pitched FLUTE-like instrument that is often used in military and marching bands. A TUBA is a large brass instrument that produces a deep sound and is usually the largest instrument in a marching band. A DRUM is a percussion instrument that is used to create a beat and rhythm in a marching band. Lastly, a FLUTE is a woodwind instrument that produces a light, airy sound and is often used in marching bands.