or shortens the tube, and thus changing the key of the instrument, acquires all the tones which can be obtained from so many tubes of different lengths.  The mouth-pieces of the trumpet, trombone, and tuba are cup-shaped, and larger than the mouth-piece of the horn, which is little else than a flare of the slender tube, sufficiently wide to receive enough of the player’s lips to form the embouchure, or human reed, as it might here be named.

[Sidenote:  The French horn.]

[Sidenote:  Manipulation of the French horn.]

The French horn (Plate IX.), as it is called in the orchestra, is the sweetest and mellowest of all the wind instruments.  In Beethoven’s time it was but little else than the old hunting-horn, which, for the convenience of the mounted hunter, was arranged in spiral convolutions that it might be slipped over the head and carried resting on one shoulder and under the opposite arm.  The Germans still call it the Waldhorn, i.e., “forest horn;” the old French name was cor de chasse, the Italian corno di caccia.  In this instrument formerly the tones which were not the natural resonances of the harmonic division of the tube were helped out by partly closing the bell with the right hand, it having been discovered accidentally that by putting the hand into the lower end of the tube—­the flaring part called the bell—­the pitch of a tone was raised.  Players still make use of this method for convenience, and sometimes because a composer wishes to employ the slightly muffled effect of these tones; but since valves have been added to the instrument, it is possible to play a chromatic scale in what are called the unstopped or open tones.

[Sidenote:  Kinds of horns.]

[Sidenote:  The trumpet.]

[Sidenote:  The cornet.]

Formerly it was necessary to use horns of different pitch, and composers still respect this tradition, and designate the key of the horns which they wish to have employed; but so skilful have the players become that, as a rule, they use horns whose fundamental tone is F for all keys, and achieve the old purpose by simply transposing the music as they read it.  If these most graceful instruments were straightened out they would be seventeen feet long.  The convolutions of the horn and the many turns of the trumpet are all the fruit of necessity; they could not be manipulated to produce the tones that are asked of them if they were not bent and curved.  The trumpet, when its tube is lengthened by the addition of crooks for its lowest key, is eight feet long; the tuba, sixteen.  In most orchestras (in all of those in the United States, in fact, except the Boston and Chicago Orchestras and the Symphony Society of New York) the word trumpet is merely a euphemism for cornet, the familiar leading instrument of the brass band, which, while it falls short of the trumpet in the quality of its tone, in the upper registers especially, is a more easily manipulated instrument than the trumpet, and is preferable in the lower tones.