The origins of the Tuba
Twists and Turns in the Development of the Tuba

Three years after inventing the basstuba, Moritz created the tenor tuba, an instrument with a higher tonal range. A fellow German named Ferdinand Sommer made the tubes of the tenor tuba thicker and more tapered. He called this instrument the "euphonium." The name was taken from "euphonos," which means "beautiful sound" in Greek.

While Sommer was developing the euphonium in Germany, Adolphe Sax, noted father of the saxophone, was creating one saxhorn instrument after another in Paris. First the sopranino, then the soprano, alto, tenor, and baritone saxhorns all had high tonal ranges that exactly matched the increasingly popular euphonium. The bass saxhorn, in fact, was sold under the name euphonium and was a great success.
Incidentally, the baritone saxhorn made by Adolphe Sax became the prototype for the modern baritone, which, although seldom used in typical brass bands, is an indispensable instrument in British-style brass bands.

As various brass instruments with low tones were being created, the one with the deepest pitch came in the 1840s by a Czech craftsman named V. F. Červený. A modern tuba is typically a C or B♭ tuba. As an instrument, the tuba can have various pitches, but these were not all invented by the same person. Craftsmen in various situations came up with diverse ideas and created instruments that were vetted in actual use, eventually leaving us with the instruments we use today. As a group, we call them tubas.