The contrabassoon is a very deep-sounding woodwind instrument that plays in the same sub-bass register as the tuba, double bass, or contrabass clarinet.

At the lower end, Richard Bobo of the Tulsa Symphony has designed a "subcontrabassoon", a full octave below the contrabassoon, and is intent on manufacturing the first working prototype.

Conversely, contrabassoon also has a booming quality, similar to organ pedals, in its lowest register; enabling it to produce powerful contrabass tones when desired (aided by the flared bell, which the bassoon does not have).

Precursors to the contrabassoon are documented as early as 1590 in Austria and Germany, at a time when the growing popularity of doubling the bass line led to the development of lower-pitched dulcians.

In 2000, Heckel announced a completely new keywork for its instrument and Fox introduced its own new key system based on input from New York Philharmonic contrabassoonist Arlan Fast.

The contrabassoon is a supplementary orchestral instrument and is most frequently found in larger symphonic works, often doubling the bass trombone or tuba at the octave.

9, just prior to the tenor solo), although Bach, Handel (in his Music for the Royal Fireworks), Haydn (e.g., in both of his oratorios The Creation and The Seasons, where the part for the contrabassoon and the bass trombone are mostly, but not always, identical), and Mozart had occasionally used it in other genres (e.g., in the Coronation Mass).

[6] As a featured instrument, the contrabassoon can be heard in several works, most notably Maurice Ravel's Mother Goose Suite, and at the opening of Piano Concerto for the Left Hand.

Gustav Holst gave the contrabassoon multiple solos in The Planets, primarily in "Mercury, the Winged Messenger" and "Uranus, the Magician".

[5] Solo literature is somewhat lacking, although some modern composers such as Gunther Schuller, Donald Erb, Michael Tilson Thomas, John Woolrich, Kalevi Aho, Ruth Gipps and Daniel Dorff have written concertos for this instrument (see below).

Besides occasional gigs with orchestras and other ensembles (including regular substitute with the Chicago Symphony), her main work is as soloist and recording artist.

[13] A rare use of the instrument in jazz was by Garvin Bushell, who sat in as a guest with saxophonist John Coltrane during his 1961 recording sessions at the Village Vanguard.