This Section
next Fifth Method.
The fifth method by which the air-column can be set in vibration is, as we have stated, the method now employed by all the Orchestral and Military Brass. A mouthpiece (almost always of metal) is placed at the upper end of the tube. This mouthpiece is either cup-shaped, funnel-shaped, or a mixture of the two. The player's lips stretch across the mouthpiece and themselves act as the vibrating reeds. The shape of the mouthpiece, especially the shape of its lower portion, is the main determining factor in the tone-quality of the instrument. " The shallower the cup the more brilliant the tone." The shallow " cup " is characteristic of the Trumpet: the broad deep " cup " of the modern " Tubas." On the other hand, the funnel-shaped mouthpiece is used for the Horns. To this they owe their warmer and less incisive tone-colour. A hybrid cup-and-funnel-shaped mouthpiece is used for the Bugle.
The group which employs this, the fifth method of tone-production, includes all the Brass, ancient as well as modern, as well as the obsolete Zinke and the Serpent. It might of course be subdivided according to the shape of mouthpiece used. Such a subdivision, however, would be like that of the Single- and Double-Reeds merely one of tone-colour. It is better, as in the former case, to base the subdivision on the integral characteristics of the tubes themselves. As these tubes, whether they are conical or cylindrical, all produce the same series of notes, we can make our subdivision depend solely on the natural methods of each instrument for altering the length of its air-column. The subdivision will then take the following form:
(1) Tubes of fixed length, which can therefore only produce a single series of notes at a time. The best examples are the Natural Trumpet, the Natural Horn, and the Military Bugle.
(2) Tubes in which the length of the air-column is varied by means of holes pierced laterally. The best examples are the Keyed-Bugle, the family of Ophicleides, and the Russian Bassoon. All of these instruments were made of brass and are now obsolete.
(3) Tubes in which the length of the air-column is varied by means of Valves, or Pistons. The best examples are the Valve-Trumpets, the Cornets, the Valve-Horns, the Saxhorns, the Flügel-horns, the Valve-Trombones, and the modern "Tubas." As will be
Ivory and bone were often used. Even at the present-day ivory mouthpieces are occasionally employed by Tuba-players.
See page 90 for fuller details on this point.
For fuller details, see the preliminary matter before the section devoted to Brass instruments.
The Russian Bassoon and the Bass-Horn were transition-instruments between the Serpent and the Ophicleides. The student should group together in his mind these six instruments of the "Cup-mouthpiece and laterally-pierced" type in their historical order,—the Zinke, tlie Serpent, the Russian Bassoon, the Bats-Horn, the Ophicleide, and the Keyed-BuiJle. Of these, all but the first two were made of brass.
For a description of the so-called "Wagner Tubas" see page 151 et seqq.