1911 Encyclopædia Britannica/Sordino
SORDINO, Sordoni, Sorduni, Italian terms somewhat promiscuously applied by various writers (1) to contrivances for damping or muting wind, string and percussion instruments (Sordini); (2) to a family of obsolete wind instruments blown by means of a double reed (Sordoni or Sordun); (3) to a stringed instrument. To these must also be added the Surdellina or Sordellina, a kind of musette invented (see Bagpipe) in Naples in the 17th century, and evidently named after class 2.
consisted of a hollow cone of wood or cardboard, truncated at the apex to allow the air to pass through and escape through a hole in the base. The bore of the instrument thus continued through the cone of the mute was the essential point, and the proportions to be maintained between the diameters of the two bores were also, no doubt, of importance. Domnich expressly states that it was when Hampel substituted a plug of cotton-wool (therefore solid and providing no central passage for the air) for the mute, that he found the pitch of the horn raised a semi-tone. Domnich's evidence is of value, for his father was a horn-player contemporary with Hampel, and he himself was the intimate friend and colleague ofPunto, Hampel's most celebrated pupil.
description of the construction and acoustic properties of the sordoni will clear up the mystery. The body consisted of a cylinder of wood in which were cut two parallel channels of narrow cylindrical bore, communicating with each other at the bottom through a bend, but not with ambient air. At the top of the cylinder was fitted a double-reed mouthpiece giving access to the column of air at one end of the bore, while the other was vented through a small hole in the side, similar to the finger-holes; in the tenor, bass and contra members of the family, the reed was attached to a curved brass crook similar to that of the fagotto. So far the description would almost apply to the dolcian also, but in the latter there is the radical difference that the bore of the channels is conical, so that it has the acoustic properties of the open pipe. The sordun, however, having a cylindrical bore, has the acoustic properties of the stopped pipe, i.e. the sound waves are twice the length of the pipe, so that to produce a sound of any given pitch, for instance for C, the bore need only be half the length, i.e. 4 ft. long. Over-blowing, on the sordoni, moreover, produced as first harmonic (the only one required for reed-blown instruments in order to produce the diatonic scale for the second octave) not the octave, but the twelfth, or number 3 of the series. This accounts for the fact that instruments of the fagotto and dolcian type require but 6 or 7 holes to give the diatonic scale throughout the compass, whereas the sordoni require 11 or 12 holes. Praetorius states that those figured by him (Plate XII.) have 12 open holes, and that some specimenshave in addition two keys; a hole is also bored through the bottom of the instrument to allow the moisture condensed from the breath to be shaken out. The 12 holes are stopped by means of fingers and thumbs and by the ball of the hand or the fleshy under-part of the joints of the fingers. The compass of the 5 sizes of sordoni was as follows: —
- See Victor Mahillon, “Le Cor,” Instruments à vent, pt. ii. (Brussels and London, 1907), pp. 34 and 53.
- Méthode de premier et de second cor (Pans, c. 1807), pp. 3 and 4.
- Vollständige theor.-prakt. Musiklehre für alle bei dem Orchester gebräuchliche Instrumente (Cologne and Bonn, c. 1811).