TOURNEBOUT, a wind instrument of wood, in which a cylindrical column of air is set in vibration by a reed. The lower extremity is turned up in a half circle, and from this peculiarity it has gained the French names tournebout and cromorne, - the latter a corruption of the German name Krummhorn. There appears to be no English equivalent. The reed of the tournebout, like that of the bassoon, is formed by two tongues of cane, adapted to the small end of a conical brass tube, the large end being inserted in the body of the instrument. It presents, however, this difference, that it is not, like that of the bassoon, in contact with the player's mouth, but is covered again by a cap pierced with a hole in the upper part, through which opening the air is introduced which sets the reed in vibration, the reed being therefore subject to no pressure of the lips. The compass of the instrument is naturally limited to the simple fundamental sounds which the successive opening of the lateral holes gives rise to. The tournebonts have not much length for the deep sounds they produce, which arises from these instruments sounding, like all tubes of cylindrical bore provided with reeds, the same as the stopped pipes of an organ. That is to say, theoretically pipes of an organ, or for conical tubes provided with reeds, to produce notes of the same pitch. Moreover, when, to obtain a harmonic, the column of air is divided, the tournebout will not give the octave like the oboe and bassoon, but the twelfth, corresponding in this peculiarity with the clarinet and all stopped pipes or bourdons. With the ordinary boring of eight lateral holes, the tournebout possesses a limited scale embracing a ninth. Sometimes, however, the deeper sounds are completed by the addition of one or more keys. By its structure the tournebout is one of the oldest wind instruments ; it is evidently derived from the Greek aulos and the Roman tibia, which consisted equally of a simple cylindrical pipe of which the column of air was set in vibration by a double reed.
Notwithstanding the successive improve- it ments that were introduced in the manufacture of wind instruments, the tournebout scarcely ever varied in the details of its construction. Such as we see it represented in the treatise by Virdungl we find it again about the epoch of its disappearance, in L' Art du Faiseur d'Instruments de l'Encydopedie de Diderot et d'Alembert (Paris, 1751-80).
The tournebouts existed as a complete family from the 15th century.
According to Virdung, it was formed of four individual instruments; Pratorius2 cites five, - the deep bass, the bass, the tenor or alto, the cantus or soprano, and the high soprano, with com and torius, an "aceort," of tournebouts comprecantus (soprano), 1 high soprano.-9.
The tournebouts were not always an orchestra by themselves ; they allied themselves also to other instruments, and notably to flutes and oboes. It was thus that the little groups of musicians in the service of princes, or those engaged by some large town on the occasion of a festival or public ceremony, were composed of several tournebout players combined with some flautists and oboe players. In 1685 the orchestra of the Neue Birche at Strasburg comprised two tournebouts, and until the middle of the last century these instruments formed part of the music called "la grande ecurie " in the service of the French kings. Tournebouts have in our days become of extreme rarity, and scarcely exist in collections. The museum of the Conservatoire Royal de Musique at Brussels has the good fortune to possess a complete family, which is regarded as having belonged to the duke of Ferrara, Alphonso II. d'Este, a prince who reigned from 1559 to 1597. The soprano (cantus or distant) has the same compass as above, while the alto, the tenor (furnished with a key), and bass have an extent respectively of , and a: The bass (see accompanying figure), besides having two keys, is distinguished from the others by a kind of small bolt, two of which slide in grooves and close the two holes that form the lowest notes of the instrument. It is very curious to observe that the employment of these bolts, placed at the extremity of the tournebout and out of reach of the fingers of the instrumentalist, forces him to require the assistance of a person whose sole mission is to attend to these bolts during the performance.
The "Platerspil of which Virdung gives a drawing is only a kind of tournebout. It presents especially the peculiarity that, Muska getutscht uncl autzgezogen, Basel, 1511. 2 Organographia, Wolfenbiittel, 1618.
instead of having a cap to cover over the reed, there is a spherical receiver surrounding the reed, to which the tube for insuffiation is adapted. This receiver was of wood worked round, ur perhaps consisted of a simple gourd. (V. M.)