Sound is produced according to the same principles as on the bassoon:
The double reed is placed between the lips and blown, which sets the two reeds vibrating against each other. They open and close very quickly, thereby sending little puffs of air into the air column inside the instrument, which is stimulated to move in sympathy.
Because the air column inside the contrabassoon’s tubing is 550 cm long the sound takes longer to develop fully than on the bassoon.
As on all woodwinds it is primarily the keywork that is used to produce the various pitches. The technique of overblowing – the bassoon overblows to the octave – is largely replaced by the use of speaker keys.
All of the tone holes on the contrabassoon are closed using keys. With the exception of the highest notes the fingering is the same as on the bassoon.
Because it weighs about 6 kg the contrabassoon is played in the sitting position. It has a spike at the bottom on which it rests on the floor and is held on a strap round the neck. Both thumbs are thus free for playing.