REED, in music, the mouthpiece of a hautboy, bassoon, or clarionet. Also, a piece of metal with a brass spring or tongue attached to it in such a way that the admission ,:f a current of wind causes it to vibrate and sound a musical note. The reed is of two kinds, the beating reed and free reed. The former is used in the reed-pipes of an organ (q. v.), and requires to be placed within a tube in order to produce a musical sound. It C.?nsists of a metallic cylinder, with the front part cut away, and a brass spring cr placed against the opening, and attached at the upper end. The admission of air to the pipe in which the reed is placed causes the tongue to vibrate against the edge of the opening, so as to cover and uncover the slit, through which the air passes to the pipe above, the regularly repeated beat producing a musical note, dependent for its pitch on the length of the tongue, which is regulated by a strong spring of wire pressing against it. The quality of the sound is determined to a large extent hy the length arid of the pipe in which the reed is placed. The free reed differs from the beating
reed in this, that the tongue is a little smaller than the opening, and strikes, not the edge of the opening, but the air. The admission of a current of wind causes it to yield en as to let the air pass, while, after recovering its position, it is carried by its momentum equally far on the other side, and continues vibrating so long as the current of air is continued, the result of the pulsations being a musical note. The invention of the free reed has been ascribed to M. Grenie, a Frenchman, who brought it into use, but it has been long known to the Chinese. Its note is more smooth and mellow than that of the beating reed, and it has the advantage of not requiring a pipe, which is a necessary appendage to the latter. Besides being occasionally adapted to organ-pipes, it is used without a pipe in the harmonium (q.v.).