=The Tube with a Reed=.—The next subdivision is: The tube in conjunction with a tongue or slip of cane, called a reed. Reed instruments are further divided into _single_ and _double reed_ instruments. The double reed instrument is of great antiquity and widely known. This is the instrument generally meant by the term “flute” in the ancient Greek authors. It is known in China and Thibet, and in its modern form as =Hautboy= (oboe), =English Horn= or =Bassoon=, is an important member of the modern orchestra. The beating or single reed is so-called because it is made a little larger than the orifice over which it is fixed, and therefore beats against this orifice at every vibration, closing it and causing the air to be emitted in puffs. This form of reed instrument is also widely distributed. By the Greeks it was called the Berecynthian pipe; in modern Egypt _Arghool_, in early England the Shawm, which is a corruption of an older French name—_Chalumeau_. Under the name =Clarinet= it is another important member of the orchestra. The beating reed also furnishes the model after which the reed stops of the organ are constructed. =The Tube with the Lips of the Player=.—The last subdivision is the tube in conjunction with the lip of the performer, the lips assuming the rôle of the reed. Countless varieties of =trumpets= have been used from time immemorial, made at first from that natural tube that has given them their generic name, the “horn” of the ox or goat or antelope. The forms of the horn are endless, but from the conch shell of the Japanese or the ram’s horn _Shofar_ of the Hebrews to the perfectly tuned and mechanically perfect instruments of our bands and orchestras the series is complete, and the acoustic principle in all respects identical. =Stringed Instruments Played by Plucking=.—The stringed instruments are those which depend for their sound upon the vibration of stretched strings. This class of instruments is of very ancient origin. As in the case of the wind instruments, the discovery of the principle of the vibration of a stretched string was probably accidental. The twanging of a bow-string suggests a possible clue, or the membranes of animals used for any purpose in which tension is required. Earliest among stringed instruments are the various forms of =Harp= or =Lyre=, in which each string gives a single sound, and is put in motion by being _plucked_ by the finger or _struck_ by a rod or flat strip of wood, ivory, etc., called a _plectrum_. In the next class are included those instruments that are furnished with a neck or fingerboard, with or without frets. In this class the strings are comparatively few in number, as many sounds may be obtained from each string by altering its length by the pressure of the fingers on the neck. These instruments are also played either with the fingers or the plectrum; to this class belong the =Guitar=, =Lute=, =Mandolin=, etc.