From Academic Kids
The cornett takes the form of a tube, typically about 60 cm. long, made of ivory or wood with woodwind-style fingerholes. Usually the cornett is octagonal in cross-section, and it is wrapped in leather or parchment, with the fingerholes penetrating this cover. The cornett is slightly curved, normally to the right, so that the player's left hand, playing the upper holes, and her right hand, playing the lower holes, can more comfortably reach their proper locations. At the top of the cornett there is a small mouthpiece of the kind used in brass instruments; that is, it is vibrated with the lips.
The cornett is thus an unusual specimen among wind instruments, with a body constructed like a woodwind but its mouthpiece (and thus mechanism of tone production) being that of a brass instrument. Scholars evidently agree that the latter criterion is more important, and so the cornett should be counted as brass. In particular, the Hornbostel-Sachs system of musical instrument classification places it alongside instruments such as the trumpet.
Purist cornett players tend to use a smaller mouthpiece, whereas those needing to make a compromise--often with the need to go on playing modern brass instruments--may use a much larger mouthpiece, sometimes a trumpet mouthpiece ground down on a lathe so that only the cup and a minimal stub which fits the cornett's mouthpiece receiver are left.
Music for the cornett
Historically, the cornett was frequently used in consort with sackbutts (2 cornetts, 3 sackbutts), often to double a church choir. This was particularly popular in Venetian churches such as the Basilica San Marco, where extensive instrumental accompaniment was encouraged, particularly in use with antiphonal choirs. Giovanni Bassano was an example of a virtuoso early player of the cornett, and Giovanni Gabrieli wrote much of his resplendent polychoral music with him in mind. [[Heinrich Sch?also used the instrument extensively, especially in his earlier work; he had studied in Venice with Gabrieli and was acquainted with Bassano's playing.
The cornett was, like almost all Renaissance instruments, made in a complete family; the different sizes being the high cornettino, the cornetto, the tenor cornett (or lizard) and the rare bass cornett (the serpent was preferred to the bass cornett). Other versions include the mute cornett, which is a straight narrow-bore instrument with no mouthpiece, quiet enough to be used in a consort of viols or even recorders.
The cornett was also used as a virtuoso solo instrument, though not much cornett music survives. The use of the instrument had largely died out by 1700. It was last scored for by Gluck, in his opera Orfeo ed Euridice (he suggested the soprano trombone as an alternative). As a point of interest, Gluck was also the last person to score for the recorder, in the same opera.
Playing the cornett
The cornett is generally agreed to be a difficult instrument to play. It embodies a design that survives in no modern instrument; that is, the main tube has only the length of a typical woodwind, but the mouthpiece is of the brass type, relying on the player's lips to form the musical sound. Most modern brass instruments are considerably longer than the cornett, which permits the tube resonances to be used more effectively in controlling pitch.
The Baroque era was relatively tolerant of bright or extroverted tonal quality, as the surviving organs of the time attest. Thus the Baroque theorist Marin Mersenne described the sound of the cornett as "a ray of sunshine piercing the shadows". Yet there is also evidence that the cornett was often badly played. Its upper register sounded somewhat like a trumpet or modern cornet, the lower register resembling the sackbutts that often accompanied it, whereas the middle register gave an indistinct wailing sound that was not attractive when played in isolation. Cornett intonation also tended to be insecure.
As a result of its design, the cornett requires a specialized embouchure that is very tiring to play for any length of time. It was inevitable that the finest players of the instrument would ultimately turn their attention to the developing oboe.
The cornett and authentic performance
As a result of the recent early music renaissance, the cornett has been rediscovered, and as before attracts the finest players. In some pieces (particularly those of early Baroque composers such as Monteverdi and [[Heinrich Sch?h? the cornett is felt to be indispensable in performance, and the music suffers if other instruments are substituted.