The bugle is one of the simplest brass instruments; it is essentially a small horn with no valves. All pitch control is done by varying the player's embouchure, since the bugle has no other mechanism for controlling pitch. Consequently, the bugle is limited to notes within the harmonic series.

The bugle is used mainly in the military and in drum and bugle corps, where the bugle has evolved away from its military origins, growing valves. Bugles in drum and bugle corps are typically pitched in G.