The "original" sousaphone. An historic design, the C.G. Conn 20K originated from the concepts of John Philip Sousa in the early 1900's. This large bore sousaphone has the most sought after sound for the marching field. Improved bracing to meet the demands of today's marching activity along with short action, offset pistons provides great versatility for any sousaphone section. Nickel plated pistons provide smooth, quick action and unmatched durability.