The term "saxtuba" may also refer to the bass saxhorn. The helicon is derived from the saxhorn, or the saxtuba. He also invented the saxotromba, saxhorn and saxtuba. A total of eight different sizes of saxtuba were required to play ten individual parts. Like the saxhorn, the saxtuba was a transposing instrument. In 1859 Sax applied his system of six independent valves to the saxtuba. The saxtuba is often mistaken for one of the larger members of Sax's saxhorn family.