Cornet (organ stop)
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A Cornet, or Jeu de Tierce, is a compound organ stop, containing multiple ranks of pipes. The individual ranks are most commonly of principal or flute tone quality. In combination, the ranks create a bright, piquant tone thought by some listeners to resemble the Renaissance brass instrument, the cornett.
The Cornet is primarily used as a solo voice and the ranks of the Cornet follow the harmonic series; 8', 4', 2 2/3', 2', 1 3/5'. The 8' rank is stopped while the other ranks are open. The Cornet may contain from two ranks and up, though three, four, and especially five ranks are the most commonly found. It is the unique reedy quality created by the tierce rank (1-3/5'), perhaps in combination with the nazard (2-2/3'), that gives the cornet its distinctive sound. The stop can be found on instruments of most historical periods and geographical regions, but the cornet was particularly important in the French Classic organ (from about 1625 to the end of the eighteenth century), which might contain three or four of them, often at different pitch levels.
The two-rank version has only the 2 2/3' and 1 3/5' ranks, but this combination is more commonly called a Sesquialtera. The three-rank version has the 2 2/3', 2', and 1 3/5' ranks; the four-rank version adds the 4' rank. Some Cornets may include more harmonics, such as the seventh (1 1/7') and in rare cases the Ninth (8/9').