| Guitar strings from the nineteenth century to the advent of Nylon - Standard Pitches |
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Page 6 of 8
STANDARD PITCHESAn important element in determining the working tensions of the guitar of that time relates to the frequency of the standard A that was in use in the nineteenth century, which varied considerably, and not only from place to place, but also in the same place from one period to another. In 1834 the Congress of Stuttgart approved a tuning standard of A = 440 Hz, but this recommendation was not followed. In 1858 the French government reported that the tuning standard of the Paris Opéra and the Opéra Italienne was A = 448 Hz, but a year later a French commission for the standardisation of tuning (composed of illustrious figures such as Halévy, Auber, Berlioz, Meyerbeer, Rossini and Thomas) - the first in Europe - established A as 435 Hz through an imperial decree. In England, orchestral pitch was A = 424 Hz in 1813, but this was raised to 452 Hz in 1859. The supposed nineteenth-century tuning standard of A = 435 Hz seems to have been an illusion rather than reality, and this is certainly true up to the second half of the nineteenth century. With the Congress of Vienna of 1885 the standard A was officially established at 870 simple vibrations, or 435 double Hz, a recommendation that was also adopted by the Italian government in 1887, but in fact the tuning standard continued to fluctuate. Only with the meeting called in 1939 by the International Organisation for Standardisation was the situation presented by the jungle of different tuning standards clarified, proposing a standard A of 440 Hz. The rest is recent history. On the basis of diameter range, vibrating length and tuning standard (for the sake convenience, A = 435 Hz), the range of working tensions of the first three strings of the nineteenth-century guitar may be calculated as follows:1st, E (325.9 Hz): 7.4-9.0 kg (average 8.2 kg) 2nd, B (244.0 Hz): 6.9-7.9 kg (average 7.4 kg) 3rd, G (193.8 Hz): 7.4-9.3 kg (average 8.2 kg) Extending these figures to all six strings, one arrives at an overall tension of 46.8 kg, which corresponds to the figures given by Aguado, who specifies an overall load of 80 or 90 pounds, i.e. 39-44 kg (1 pounds =489,5 grms; see Horace Doursher 'Dictionnaire universel des poids et measures…', Antwerp 1840, facsimile ed. Amsterdam 1965). As may be observed, these approximate working tensions are certainly higher than we would expect, and if anything rather similar to those we use ourselves. OVERSPUN BASS STRINGS
Since overspun strings are made from joining together two different kinds of material, such as metal and silk, it has become customary to describe them in terms of equivalent gut strings. In other words, we refer in calculations to the diameter of a theoretical equivalent solid gut string of the same weight as the overspun string per unit of length: at the same tuning and vibrating length it will therefore have the same working tension. It should be noted, however, that for any given equivalent solid gut string, the ratio between the metal and the silk may be endlessly varied. An increase in one material will obviously entail a reduction in the other, if the total weight of the string is to remain constant (that is, its equivalent gut string, and therefore the working tension of the tuned string). It goes without saying that the greater the prevalence of silk in relation to metal, the less brilliant and more opaque the sonority is likely to be. What criteria were used to determine the right ratio between metal and silk in bass strings, one that would guarantee a balanced sound in terms of timbre and dynamics? In the guitar the ratio was more limited than in bowed string instruments: once the working tension had been decided on, the proportions between metal and silk were calculated so as to produce the greatest volume of sound, using the thickest possible metal wire and at the same time reducing the silk core to a minimum, almost to the breaking load of the string when in tension on the instrument. In spite of this measure, overspun silk strings - even those that have remained in their packets - sound rather percussive to our ears, and lacking in upper overtones.
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