The tuba is the deepest sounding instrument of the brass family and provides the bass notes for this group of instruments.
The tuba comes in variable shapes depending on whether it is played in brass and military bands or an orchestra.
Because the player is sitting, orchestral tubas are designed to sit on players laps as it is so heavy. The brass tube is coiled like that of a trumpet or horn. The large circular opening called the bell faces upwards and to the players left or right. There are valves which open more tubing and make the instrument deeper in pitch. There are usually four valves but some tubas have five or six valves.
Varieties of Orchestral Tubas include:
Tenor Tuba: These have a narrowish tube and a funnel shaped mouthpiece like a horn.
Bass Tuba: These are shaped like a horn.
Double Bass Tuba: These have a wide conical tube and a cup shaped mouthpiece like a trumpet.
These three types of tubas were made for Robert Wagners' Operas called The Ring of the Nibelungs.
An orchestra usually has one tuba.
Military Band Tubas:
Because the player is standing they are designed to be carried on the players shoulders.
Euphonium: Low Bb is the lowest note.
Eb Bass: This has a lower note
Double Bb Bass: This produces the lowest sound of the three instruments
Helicon: This is a circular shaped double Bb Bass
Soussaphone: This is a circular shaped Eb Bass.
You need to decide if you would like to be part of an orchestra or military band playing the low notes to your group. If you are keen to learn an instrument; do you want to learn the orchestral or military style of tuba?