The contrabass bugle is the only member of the drum corps bugle line that has never been produced in a valve-less style, as it was developed when the drum corps rules allowed one piston valve and one rotary valve. They changed to fit new rules along with the rest of the drum corps hornline, first receiving two vertical (or in this case, slanted for ease of use) piston valves, then 3 and later 4 valves to make the instrument fully chromatic.