Tuba after American bandmaster John Philip Sousa, resembles a hélicon with the bell pointed up (in the original models as the J. W. Pepper prototype and Sousa's concert instruments) and then curved to point forward (as developed by Conn and others). Some ancestors of the tuba, such as the military "bombardon", had unusual valve and bore arrangements compared to modern tubas. During the American Civil War, most brass bands used a branch of the brass family known as "saxhorns", which, by today's standards, have a narrower bore taper than tuba—the same as true cornets and baritones, but distinct from trumpets, euphoniums,
Tuba of notes. Prior to the invention of valves, brass instruments were limited to notes in the harmonic series, and were thus generally played very high with respect to their fundamental pitch. Harmonics starting three octaves above the fundamental pitch are about a whole step apart, making a useful variety of notes possible. The ophicleide used a bowl-shaped brass instrument mouthpiece but employed keys and tone holes similar to those of a modern saxophone. Another forerunner to the tuba was the serpent, a bass instrument that was shaped in a wavy form to make the tone holes accessible to the player.