PITCH, the degree of acuteness of musical sounds. A musical sound is produced by a series of vibrations recurring on the ear at precisely equal the greater the number of vibrations in a given time, the more acute or higher is the pitch. In stringed instruments the pitch is dependent on the length, the thickness, and the degree of tension of the strings; the shorter and thinner a string is, and the greater its tension, the higher is the pitch of the note. In wind instruments, where the notes are produced by the vibration of a column of air, as in the mouth-pipes of an organ, the pitch is dependent on the length of the column set in motion; the shorter the column of air, the higher the pitch becomes.
The pitch of musical instruments is adjusted by means of a tuning-fork, consisting of two- prongs springing out of a handle, so adjusted as to length that when struck a particular note is produced, that note being C in Britain, and A in Germany. It is obviously important to have a recognized standard of pitch by which instruments and voices are to be regulated; but there is. unfortunately, not the uniform ity that might be desired in the pitch in actual use. , For a long time prior to 1859 con cert-pitch had been gradually rising, to the detriment of the voices of public singers.
The C tuning-fork, in use in 1699, made 489 vibrations per second, while in 1859 the number of vibrations had increased to 538. Mr. Hullah; in 1842, in the numerous classes instituted by him under the sanction of the committee of council on education, found it necessary to secure kuniform standard of pitch, and adopted 512, which has an especial convenience as being a power of 2. The French imperial government, in 1858, fixed on 522. In 1859 a committee of the society of arts was appointed to _Aansider the subject of a uniform musical pitch. Their deliberations lasted 12 months. Sir John Herschel, it) a letter to the committee, strongly recommended the number 512. It was agreed on all hands that the then existing opera-pitch of 546 was too high and painful to the singers of soprano music. The instrumental performers stated that they could lower the to 528, but if they had to lower it to 512 some of them would have to purchase new instruments; and, in consequence apparently of their representation, the committee reported in favor of 528.