It is also called Double Bassoon. It is Twice in size as a bassoon. They are very rare and hidieously expensive. In the hands of the best musicians, the contrabassoon organlike tone rings through the orchestra, adding richness and weight to chords. Contrabassoons are almost never found in bands, but can sometimes be heard in symphony orchestras. The bassoon's tubular body is divided into four sections, and doubles back on itself to make it more manageable to play.
Some very old orchestral-transcriptions will have a part for one; and modern repertoire only very rarely calls for one and even then it is "optional". For the most part in modern band music , the role the contrabassoon played is now handled by the contrabass clarinet. If we encounter a piece of music with a contrabassoon part, we will often leave it unplayed or have our contrabass clarinet player play the part. Even in the symphony orchestra, which is where they originated from, contrabassoons are not called for very often.
