The semi-contrabassoon (also called quint bassoon, semi-contra or half-contra) is a double reed woodwind instrument pitched between the bassoon and the contrabassoon. It is pitched in either F (quint bass) or G (quart bass) a fifth or fourth, respectively, below the bassoon.
These instruments were used mostly in the 18th century and are remnants of the old quart bass dulcians. They were considered easier to make than the larger contrabassoon. A semi-contrabassoon was shaped like an oversized bassoon, between 5 and 6 feet (1.5–1.8 m) tall with a long descending bocal. Little literature exists that indicate that these instruments were used, although it is possible that they may have been used to some extent in military bands. No attempt to revive this instrument in the present day has been made. The great organist Charles Marie Widor in his book on orchestration expected that the semi-contra would be added to the orchestra’s roster.
The basson-quinte has not yet been made, but bassoon-players are calling for it. It would form the true bass of the Woodwind group, a fifth below the standard instrument, descending consequently to E♭, a semitone lower than the double bass. The low A, which Wagner wrote below B♭ is admirably rich and full; 'then', say professionals, 'why not descend to E♭, with the same fingering and the same capabilities as the ordinary bassoon?' We have already seen that the low fifth, from double B♭ to double F, is sufficiently robust to bear any weight of sound; the "new" low fifth would be still more robust. The basson-quinte is said do be easy of construction; we look to instrument makers to provide us with it in the near future.
No instruments were ever constructed on his instigation. Widor's remarks come in light of the dismal state of the French contrabassoon in the late 19th century, which was generally replaced with a contrabass sarrusophone. Famous operetta composer Arthur Sullivan is said to have owned a semi-contra in F and included parts for it in some of his operettas. Aside from the Great (quart) bass dulcians, the only modern reproductions of historical semi-contras are being made by Guntram Wolf of Germany.
- Widor, Charles Marie (2005). Manuel of Practical Orchestration. New York: Dover Publications. p. 47. ISBN 0486442691.
- Langwill, Lyndesay G. (1966). The Bassoon and Contrabassoon. W.W. Norton and Co.
- "Guntram Wolf Modern and Historical Woodwind Instruments". Guntram Wolf.