Like many contemporary brass instruments, the tuba's roots can be traced back to legendary 19th-century craftsman Adolphe Sax. The original instrument is known today as a Wagner tuba, because it was first pitched to the composer Richard Wagner, who adopted it into his orchestra in 1853 and gave the tuba its foothold in the music world. Since then, the tuba has been refined over the decades into its modern form and is now a vital instrument for brass and marching bands, orchestras and more. The four keys of tuba are BBb, CC, EEb and F. Your band or orchestra will usually determine which key instrument you need, with BBb used for marching bands and CC for orchestral play as a rule of thumb. If you have a small frame, a smaller tuba that needs a lower volume of air may be better suited to you physically than a larger model. A tuba's layout affects not only how it looks and feels, but also the way it is played. The most important difference you'll find is the compensating design of some tubas, which uses added tubing to tune the lower register. Tubas without this feature sometimes use an extra valve instead. The best choice for you comes down to your own skills and experience. Another thing to consider in a tuba is the material. While each instrument is different, some general rules apply. The base of the tuba is either yellow or gold brass, with the gold brass containing more copper and resulting in an instrument that's slightly darker in both color and tone. A tuba may also have a silver-plated or lacquer finish, of which silver-plate tubas tend to be brighter-sounding. Apart from the tuba, you will also find here its cousin, the sousaphone. Named for the composer and bandleader who popularized it, John Philip Sousa, this instrument is played most often in marching bands. Because of this, many sousaphones are made with fiberglass bells for a lighter weight and easier carry. In a concert setting, full brass sousaphones are preferred for their acoustic properties. You can also find hybrid models with a fiberglass body and brass bell to give you a balance between weight and sound. Whether you're looking at tubas or sousaphones, there are a lot to choose from. To narrow down your options, start by making a list of the exact features you wantâ€”this will let you rule some out right away. Once you've pared down the selection, choosing your new tuba or sousaphone is a much easier task.