Pedal tones (1st naturals) speak well on all conical instruments, although on large instruments they require an enormous amount of effort on the part of the player. Because of the huge demands made on the breathing, only the fundamental (1st natural, pedal tone Bb0) can be played on the contrabass tuba in Bb, and can be lowered by two steps (Ab0) at most. As a result, a maximum of three pedal notes is available, but these are very difficult to produce and are consequently hardly ever asked for.
Notes in the natural harmonic series can be played up to the 8th natural by means of overblowing. The instrument’s range therefore consists of the following natural harmonic series:
- Natural harmonic series on Bb0: from 1st–8th natural
- Natural harmonic series on A0: from 1st–8th natural (1st natural [pedal], difficult)
- Natural harmonic series on Ab0: from 1st–8th natural (1st natural [pedal], very difficult)
- Natural harmonic series from G0 down to B below B0: from 2nd to 8th natural
The chromatic scale is playable in its entirety over the whole range, with Bb0 and A0 as pedals; all the other notes in the instrument’s compass can be played as naturals 2 and above.
As a rule lower-pitched instruments have a less agile and therefore slower response than higher-pitched instruments. It takes longer for the column of air in the tube to respond: the deeper the note, the longer it needs to build up. This applies more to the contrabass tuba than to any other instrument. Tuba players have to compensate for this late response, which they do by beginning their attack prematurely – they must continually jump the gun, as it were, and remain fractionally ahead of the conductor.
A further difficulty encountered by tuba players is the fact that they sit right at the back of the orchestra amid curtains or surfaces that absorb part of the instrument’s sound. Their proximity to the timpani has a similar effect, because some of the tuba’s overtones are swallowed by the sound of the timpani.
The contrabass tuba’s range is the same as that of the bass tuba, which means that all the pieces commonly performed today could be performed by the bass tuba – a Bb0 can also be played on a bass tuba in F, and the lowest notes are equally hard to produce on both instruments. However, the even greater richness of tone and darker timbre of the contrabass tuba mean that it is preferred for parts at this pitch level. When writing for this instrument, composers and arrangers must pay particular attention to the difficulties of sound production – demands made on breathing, length of phrase, changing mutes.