The serpent is a bass wind instrument, descended from the cornett, and a distant ancestor of the tuba, with a mouthpiece like a brass instrument but side holes like a woodwind. It is usually a long cone bent into a snakelike shape, hence the name. The serpent is closely related to the cornett, although it is not part of the cornett family, due to the absence of a thumb hole. It is generally made out of wood, with walnut being a particularly popular choice. The outside is covered with dark brown or black leather. Despite wooden construction and the fact that it has finger holes rather than valves, it is usually classed as a brass; the Hornbostel-Sachs scheme of musical instrument classification places it alongside trumpets.
The serpent usually has six holes, which are ordered in two groups of three. On early models, the fingerholes were keyless, like those of a recorder. However, later models added keys as on a clarinet, although they were for additional holes (out of reach of the fingers), while the original holes remained unkeyed, and are covered or uncovered directly by the player's fingers.
The instrument is claimed to have been invented by Canon Edmé Guillaume in 1590 in Auxerre, France, and was first used to strengthen the sound of choirs in plainchant. This date for the invention of the serpent did not appear until 1743, in Jean Lebeuf's "Mémoires Concernant l'Histoire Ecclésiastique et Civile d'Auxerre". Herbert Heyde asserts the serpent evolved from a type of bass cornetto and was invented in Italy in the 16th century. Around the middle of the 18th century, it began to appear in military bands and orchestras, and Mozart used two serpentini in his 1771 opera Ascanio in Alba. Richard Wagner used the serpent in place of the double bassoon in his opera Rienzi. The instrument also appears in operatic scores by Spontini and Bellini, but it was replaced in the 19th century by a fully keyed brass instrument, the ophicleide, and later on by valved bass brass instruments such as the euphonium and tuba. After that the serpent dropped off in popularity for a period of time.
Luigi Morleo composed in 2012 "Diversità: NO LIMIT" - Concerto for Serpent and String Orchestra, World Premiere at Conservatory of Music "Nino Rota" - Monopoli (Ba) - Italy.