(Article in training)
Throughout my tenure as Coordinator of Musical Instruments at the National School of Music (1992-2004) I have had several experiences that have forced me to investigate the reason. Based on the expressions of the piano technicians and service requests, sometimes my astonishment has been enormous. These experiences revolve around certain themes, of which the principal has been around the pitch of these instruments as used in our school.
then it was my interest and my responsibility that the school pianos were attended by technicians so that there was no claim whatsoever. However, I faced constant complaints and criticism, mainly on the problem of pitch, teachers, students and even ... my wife. Something, then, was wrong about the tuning of the piano and had to be resolved. That there was no doubt.
Nor do I have doubts about the quality of their work or our technicians can perform. And for this I have enough data.
The high point came just over a year. Here's the story:
One afternoon, after the technician Benigno López tune a piano teacher in turn enters the respective cubicle and, after giving his class and use the piano tuned by Benigno, leaving the cubicle, find Benigno in the hallway and congratulated him on his work.
That same afternoon, the next teacher comes to the same cubicle, using the same freshly tuned piano and went out, fills a service request, in which he expresses in writing "when it will finally tuned the piano."
two diametrically opposed versions of a tune up done recently.
If not for the congratulations that the first teacher made to the technical perhaps the matter was not significant. But from a technical congratulate for having done a job and completely fail the same job, there is a chasm that has to be explained.
When something is not as you want or you want to be or when something is not working properly, it is normal that there is a problem. To resolve it requires an analysis. In this article I present this analysis without definitive answer yet to the problem. One answer I can give more definition, after an investigation, for which there is already a project.
initial steps I gave in this case are three:
1. Ask questions:
Do not perform technical work properly? Are the pianos out of tune constantly before the technicians have the time to return to them and make the next pitch? Will there be another problem that I not know? Around the first two questions, I continued to the next step and the third to last, read articles.
2. Isolate the factors that may be involved in the problem:
1st factor: intensity of work:
Each technician has an average of more than 60 pianos under its responsibility, which require regular, depending on the state of the piano and the use, care and abuse to be given: ¨
Tuning.
· Set.
· Restoration partial or total.
According to statistics compiled for the Establishment of the Coordination of Musical Instruments, the work to be performed by each technician, with a view to do with quality, is:
For quality work, each technician must have only 30 pianos awarded. They held:
6 pianos, tuning and restoration, work to be repeated every 5 years in the same plane
6.00 months
24 pianos, minor adjustment (3 days per piano), including contingencies for changes in moisture, quality of instrument, accidents, abuse, etc. Work done every 3 years in the same plane. 3.50 months
90 pitches, 2 hours per pitch (3 per year per piano) 180 hours total
1.25 months 1.25 months
administrative Vacation
TOTAL 12.00 months
Our technicians must perform, so both with good quality, more than twice as effective as prescribed.
2 ° factor: age and condition of the pianos
Last year I applied for an inventory of pianos for the school, including catalog every piano on her condition and the year production of the instrument. The summary of this inventory is the next :
Age of pianos. Year of manufacture
amount from 1889 to 1910 in June 1911 to 1920 July
1921-1930 1931-1940 5 5
Indefinite, after 1950 27 16
1950-1960 1961-1970 1971-1980 33 March
1981 to 1990 in December 2000 to present 20
Total: 134
State of the pianos. State Amount
A 42 B 21 C 38
D 18 E 20
Total: 139
A = Very good G = Good ...
C = Fair D = Poor E = Very Bad
The difference in amounts (139-134 existing in maintenance, is that 4 were already out of service)
3rd factor: the tuning beats:
technicians to carry a tune, tune first base in the central a tuning fork (the 440). Then tune the circle of fifths to be central to the chromatic scale tempered tuning. Every fifth to be tempered, the tune to a frequency of beats per second, the control is not based on a timer, but based on his memory rhythm. This factor may lie part of the cause of the "detuning" for the pianos. The coach, recalling the frequency of beats, does not necessarily apply the amount of beats per second or, what is, not his moment has 60 seconds, but a few seconds or less. This fact is proved that for two pianos tuning to be performed by four hands, the piano technician tunes each individually first and then check the tuning and correcting the defects to be the two pianos with the same pitch for each tone.
rhythmic memory is not, therefore, entirely accurate. So they invented clocks, timers and metronome. The tempo of a beat per second is the boundary between Long and Larghetto. I invite the reader to take a clock tick first few seconds watching the clock as a test or exercise, then wait for the second hand is at a particular point (eg. the 12) and dial, memory, sixty seconds without seeing the clock. Would you hit upon?
The hypotheses that emerge from this reasoning are twofold:
1. There are variations specific to each tuner in the perception of the frequency of beats to tune the fifth, so each makes a pitch tuner sui generis.
2. The correct perception of the fifth keyed by the technician depending on your mood, so depending on how you feel, will be his fifth temperate.
[The correct perception of these beats for a person can see recording fifth "right" (temperate) and (incorrect desafnadas) in a sequence of five (with a selection of 4 chosen and ordered poteriormente deviations of plus and minus 15, over and LEAST 10 and plus and minus 5 and a deviation from 0 Cents), of which one is the correct , the 0 Cents. The coach or player should check which of the five fifths in each sequence is heated. In an analysis technicians and piano teachers, only 16% will hit upon a deviation of \u0026lt;± 5 Cents. In another post I will insert the full report later.]
4 ° factor: state of the pile:
The hammers are part of the mechanics of hitting the piano (s) string (s). The last element in the chain, if we take the key as the first. With use, the hammers are marked by the constant action of the blow with the rope, forming as many rows as strings of each tone. If the grooves are very deep, its walls rub the strings before doing the blow, causing vibrations that it may give the impression that the string sounds dirty. This "dirt" in the tone is easily confused with " detuning. One of the tasks in the maintenance for the pianos is to rectify the surface of the pile with a groove "too" deep.
The same effect causes a greater proportion, if the jack is not centered. This occurs over time in some pile, because the mast to which is subject each pile is slightly deformed, either twisted or bent by the effect of the environment. In this case, the wall or the upper edge strikes the string groove before the groove base to do so, causing vibrations (harmonics) in the string even higher. Another task of the technician in maintaining the piano is to straighten the masts of the pile, with a flame heating and bending the mast to have the pile-centered and straight.
The problem of single blow or false to trigger a sound on a percussion instrument would include more easily. Just take a stick and try strike a xylophone key holding the first rod at the opposite end of the stick hitting area, then strike the key holding the stick around the area and, finally, holding a middle ground, feeling a balance of the stick in his hand. Is there a difference of sound in each instance? Now, try to strike the key, holding it comfortably, touching on one of its longitudinal edges. What happens?
The hypothesis that emerges from this is that the string Playing dirty "because the hammer in its imperfect (off-center or deep furrows) causes harmonic" undesirable "to give the impression of detuning.
5th factor: tonal memory:
In International Symposium on Musical Acoustics in December 2002 at the National Music School was mentioned that a person can store a frequency (being part of absolute pitch), by constantly repeating the fact, for example, in the pitch of the instrument, mainly in bowed string musicians. From this fact follows the hypothesis that a musician can memorize a tune determined (from his particular piano) performed consistently by the same technician, therefore, to use another piano, tuned by another technician, who has a memory of rate (number of seconds per minute) than the first. This second piano, therefore, sounds the musician as "tune."
3. information query written
Weinreich, Gabriel, The Coupled Motions of Piano Strings, JASA (?). In this article, Weinreich discovers that the fine tuning of the two or three strings of each note on a piano causes the piano sounds weak, "Character." A slight detuning, in contrast, helps to generate more harmonics, which the piano is heard louder.
Hall, Donald E.; Musical Acoustics, an Introduction, Wadsworth Publishing Company, Belmont, CA, 1980. (Translation by the author of this article)
The ear is capable of accepting two sounds with frequencies slightly out of proportion arithmetic. In the case of sine waves, the perception seems to be more tolerable tune (up 50 ¢ [1] ) that complex wave of tune, because the presence of harmonics of tune makes them less tolerable. Measurements of banda music, played by professionals, indicate that tune of 10 ¢ and 20 ¢ are common, ie go unnoticed by the listener musically trained . (Braun, 439).
[1] ¢ = Cents, a hundredth of a semitone in the tempered scale.
Miguel Zenker
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