Some of the questions answered below
The bass voice in the brass family, the tuba is both fun and challenging to learn. There are many different kinds of tubas, making them an instrument that can be used in various types of music. While most orchestras and bands use BBb or CC tubas, there are also BBb, CC, EEb, and F tubas available. Tubas are manufactured in a variety of sizes to suit a players physical attributes. This includes various tuba bore sizes to accommodate a player's ability to deliver air.
BBb and CC Tubas
Materials and Finish
Typically made with gold brass or yellow brass, tubas also have parts constructed from nickel-silver. Compared to yellow brass tubas, the metal color and sound of a gold brass tuba is darker, since gold brass consists of a higher copper content. Tubas that have a nickel-sliver trim resonate differently, and are mainly for intermediate or professional use. Lacquer and silver-plated tubas are also available. Silver-plated tubas have a brighter sound than lacquer tubas. A lot of performers enjoy a mixture of piston valve tubas with a silver-plated finish, or rotary valve tubas with lacquer finishes.
A Matter of Fractions
Because tubas come in a variety of different sizes, manufacturers came up with a system to categorize the instrument into four common sizes: 3/4, 4/4, 5/4, and 6/4. These sizes correspond to each manufacturer's instrument line. For example, a manufacturer's 4/4 is bigger than their 3/4, but their 4/4 could be smaller than a 3/4 made by another manufacturer. Of course, these size designations are simply guidelines.
Not unlike the euphonium, tubas also come in 3-, 4-, or 5-valve versions. The addition of the fourth valve aids in both low-register intonation and low-register production. As a rule, remember that at least 4 valves are required to perform and produce all the low range notes in the daily life of a tubist. The fifth valve allows the tuba to be more functional and facilitates a wider array of finger patterns to enhance a performers intonation skills.
Tubas come in a choice of rotary valves or piston valves. Similar to the valves on a trumpet, piston valves move up and down to forward air into various combinations of tubing, for the purpose of changing notes. These extend the length of the instrument. Rotary valves direct air into various tubing paths by rotating. Piston valves come on most student tubas, as well as intermediate and professional tubas; but most intermediate and professional models have rotary valves. Rotary valves also require a smaller amount of action to operate, which leads to a more flowing sound.