The Tuba
Although it is unlike them in almost every way, this fine noble instrument - easily the deepest member of the brass section is usually associated with the trombones. It also is similar to the horn and the trumpet in that it makes use of valves - 4 in number, and these provide a complete chromatic scale based on the tubas fundamental note. Probably the first major work to make use fully of the tuba was Berlioz "Symphonie Fantastique" which was originally intended to feature two ophicleides but was later changed by Berlioz to include two tubas in their place after the composer had become aware of the newly invented instrument.

There are at least four 'bass tubas' which can be found commonly used and they vary in size and weight:
- The tuba in F. - a fairly lightweight instrument long considered to be the standard orchestral bass tuba throughout Europe.
- The tuba in E-flat - this is the standard tuba in the UK often used by orchestral players because of its more sonorous lower range but very frequently found in band setups.
- The tuba in C - this is the default tuba used in American orchestras.
- The great double B-flat tuba - almost exclusively used in brass bands merely because the other band instruments are usually based on a B-flat tonality.