HANDBOOK OF ACOUSTICS - online book

A complete view of Acoustical Science & its bearings on music, for musicians & music students.

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112                    HAND-BOOK OF ACOUSTICS.
the reed will also be strengthened, but to a much less extent; for the force necessary to produce segmental vibration, increases rapidly as the number of segments increases. The higher partials of the reed are therefore practically unsupported by the associated pipe. It is evident that the pipe associated with a reed, may be selected to resound to one of the overtones of the reed, instead of to the fundamental, the resulting tone being in this case of quite different quality to the above. The form of the pipe may also vary, producing other changes in the quality of tone produced. It is thus that the varieties of reed pipes in the organ are obtained.
Fig. 60 shows how the reed is inserted in the organ pipe. V is the socket in which the lower end of the pipe is fixed, I is the beating reed, which is tuned by increasing or diminishing its effective length, by means of the movable wire d, sliding in the block, s.
The reed instruments in use in the orchestra, may be classified into the wood wind instruments, which have wooden reeds, and the brass wind instruments, which have cupped mouth-pieces. The chief instru­ments of the former class are the Clarinet, the Hautbois or Oboe, and the Bassoon. In these instruments the proper tones of the reeds themselves are not used at all, being too high and of a shrill or screaming quality; the tones employed are those de­pending on the length of the column of air in the tube, as determined by the opening or closing of the apertures. The vibration of the air column thus controls the yielding reed, which is compelled to vibrate in sympathy with it.
The Clarionet or Clarinet has a cylindrical tube terminating at one end in a bell. At the other end is the mouth piece, which is of a conical shape, and flattened at one side so as to form a kind of table for the reed, the opposite side being thinned to a chisel edge. The bore of the instrument passes Fig. 60.               through the table just mentioned, which