Pitch (music)

In music, pitch is the perception of the frequency of a note. For example, the A above middle C is nowadays set at (often written as "A = 440 Hz", and known as concert pitch), although this has not always been the case (see "Historical pitch standards"). Pitch is often cited as one of the fundamental aspects of music.

Historical pitch standards

As well as various systems of musical tuning being used to determine the relative frequency of notes in a scale, various pitch standards have been used historically to fix the absolute position of the scale. In 1955, the International Organization for Standardization fixed the frequency of the A above middle C at 440 Hz, but in the past, various frequencies have been used.

Related Topics:
Musical tuning - International Organization for Standardization

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Until the 19th century, there was no concerted effort to standardize musical pitch and the levels across Europe varied widely. Even within one church, the pitch used could vary over time because of the way organs were tuned. Generally, the end of an organ pipe would be hammered inwards to a cone, or flared outwards to raise or lower the pitch. When the pipe ends became frayed by this constant process, they were all trimmed down, thus raising the overall pitch of the organ.

Related Topics:
19th century - Organ

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Some idea of the variance in pitches can be gained by examining old tuning forks, organ pipes and other sources. For example, an English pitchpipe from 1720 plays the A above middle C at , while the organs played by Johann Sebastian Bach in Hamburg, Leipzig and Weimar were pitched at A = , a difference of around four semitones. In other words, the A produced by the 1720 pitchpipe would have been at the same frequency as the F on one of Bach's organs.

Related Topics:
English - Pitchpipe - Organ - Johann Sebastian Bach - Hamburg - Leipzig - Weimar - Semitone

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Pitch levels did not just vary from place to place, or over time - pitch levels could vary even within the same city. The pitch used for an English cathedral organ in the 17th century for example, could be as much as five semitones lower than that used for a domestic keyboard instrument in the same city.

Related Topics:
17th century - Keyboard instrument

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Readers should also refer to Helmholtz: 'On the sensation of tone".

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The need to standardize pitch levels, at least within one city or country, rose as performance of music which combined the organ with instrumental ensembles became more popular. One way in which pitch could be controlled was with the use of tuning forks, although even here there was variation - a tuning fork associated with Handel, dating from 1740, is pitched at A = , while a later one from 1780 is pitched at A = , almost a semitone lower. Nonetheless, there was a tendency towards the end of the 18th century for the frequency of the A above middle C to be in the range of to .

Related Topics:
Organ - Ensembles - Tuning fork - Handel - 18th century

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Throughout the first half of the 19th century, there was a tendency for the pitch used by orchestras to rise. This was probably largely due to orchestras competing with each other, each attempting to fill increasingly large concert halls with a brighter, more "brilliant", sound than that of their rivals. They were helped in this endeavour by the improved durability of the violins' E-strings - in the 16th century, Michael Praetorius had rejected various high pitch standards as leading to snapped strings, but the new strings could take the higher tension without breaking.

Related Topics:
19th century - Orchestra - Violin - 16th century - Michael Praetorius

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The rise in pitch at this time can be seen reflected in tuning forks. A 1815 tuning fork from the Dresden opera house gives A = , while one of eleven years later from the same opera house gives A = . At La Scala in Milan, the A above middle C rose as high as .

Related Topics:
Dresden - Opera - La Scala - Milan

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The most vocal opponents of the upward tendency in pitch were singers, who complained that it was putting a strain on their voices. Largely due to their protestations, the French government passed a law on February 16, 1859 which set the A above middle C at 435 Hz. This was the first attempt to standardize pitch on such a scale, and was known as the diapason normal. It became quite a popular pitch standard outside of France as well.

Related Topics:
French - February 16 - 1859

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There were still variations, however. The diapason normal resulted in middle C being tuned at approximately . An alternative pitch standard known as philosophical or scientific pitch, which fixed middle C at exactly (that is, 28 Hz), and resulted in the A above it being tuned to approximately , gained some popularity due to its mathematical convenience (the frequencies of all the Cs being a power of two). This never received the same official recognition as A = 435, however, and was not as widely used.

Related Topics:
Middle C - Power of two

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In 1939, an international conference recommended that the A above middle C be tuned to 440 Hz. This standard was taken up by the International Organization for Standardization in 1955 (and was reaffirmed by them in 1975) as ISO 16. The difference between this and the diapason normal is due to confusion over which temperature the French standard should be measured at. The initial standard was A = , but this was superseded by A = 440 Hz after complaints that 439 Hz was difficult to reproduce in a laboratory owing to 439 being a prime number.

Related Topics:
International Organization for Standardization - Prime number

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Despite such confusion, A = 440 Hz is now used virtually world wide, at least in theory. In practice, as orchestras still tune to a note given out by the oboe, rather than to an electronic tuning device (which would be more reliable), and as the oboist himself may not have used such a device to tune in the first place, there is still some variance in the exact pitch used. Solo instruments such as the piano (which an orchestra may tune to if they are playing together) are also not universally tuned to A = 440 Hz. Overall, it is thought that the general trend since the middle of the 20th century has been for standard pitch to rise, though it has certainly been rising far more slowly than it has in the past...

Related Topics:
Oboe - 20th century

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Readers should also consult Helmholtz: 'On the sensations of tone'.

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