LECTURE II


CHARACTERISTICS OF TONES

STANDARD PITCHES




Musical pitch is usually specified by giving the number of vibrations of the note called "Violin A," though sometimes it is given by "Middle C," or by the C an octave higher. The standard of musical pitch has varied greatly, even within the history of modern music, from the classical pitch at the time of Handel and Mozart, when it was A = 422, to the modern American Concert pitch of A = 461.6, a change of more than one and a half semi-tones. Ellis gives a table of two hundred and forty-two pitches, showing values for A ranging from 370 to 567, that is, from F# to D of the modern musical scale. (19) The conditions of use and cause of changes in pitch are described in the references. Especially interesting are the accounts of the changes in Philharmonic Pitch, that of the London Philharmonic Orchestra, which under Sir George Smart, in 1826, was A = 433, and under Sir Michael Costa, in 1845, was raised to A = 455. In America, (20) the equivalent of this Philharmonic Pitch is often referred to as Concert Pitch, and it has reached the high limit of A = 461.6. Not only has the rise in pitch been so great that artists have refused to sing and instrument strings frequently break under the strain, but the lack of uniformity also causes great confusion and trouble.

A convention of physicists in Stuttgart in 1834 adopted Scheibler's pitch of A = 440, which has been much used in Germany; this is perhaps the first standard pitch.

As a result of Koenig's researches with the clock-fork, the French "Diapason Normal," A = 435 at the termperature of 20° C., was established in 1859. This was adopted by several of the leading symphony and opera orchestras; the Boston Symphony Orchestra adopted this pitch upon its organization in 1883.

A committee of the Piano Manufacturers' Assocation of America, of which General Levi K. Fuller was chairman, made an extensive investigation of musical pitch, assisted by Professor Charles R. Cross of Massachusetts Institute of Technology. After consultation with many authorities in this country and Europe, the Committee, in 1891, adopted as the standard the Diapason Normal as determined by Koenig and named it "International Pitch, A = 435," at a temperature of 20° C. (68° F.). This is often called Low Pitch in distinction from Concert or Philharmonic Pitch, which is now referred to as High Pitch. The committee selected as its fundamental standard the type of fork made by Koenig, shown in Fig. 41, which is provided with an adjustable cylindrical resonator and gives a tone of great strength and purity.

It has been proposed that A = 438 be made a standard, as a compromise between the Stuttgart A = 440 and the Diapason Normal A = 435; for the practical purposes there is little difference in the pitches 435, 438, and 440; but there should be but one nominal standard, and it seems the strongest arguments favor the universal adoption of A = 435. The musician should insist that his piano and other instruments be tuned to this pitch.

Before any standard had been generally established for musical purposes, Koenig adopted one for hiw own work, and as tuning forks of his make are widely used in scientific instutions, this pitch, in which middle C = 256, is often referred to as Scientific or Philosophical Pitch.

The author urges the use of one pitch only for both scientific and musical purposes, viz. A = 435; in the tempered musical scale this gives for middle C 258.65 vibrations per second. This pitch is used exclusively in discussing the results of our sound analysis. In the laboratory of Case School of Applied Science the scale forks based C = 256 have been duplicated with new forks based on A = 435; Fig. 42 shows the larger part of this collection, there being over two hundred forks in the picture.

4/19/95.20:48 - 4/21/95.17:26