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FROM "The Piano Owners Guide (How to buy and care for a piano)" By Carl Schmeckel WHAT IS MEANT BY RAISING OR LOWERING PIANO PITCH? HOW DOES THIS DIFFER FROM TUNING? Raising or lowering piano pitch and tuning a piano to be harmonious are entirely different matters and they are done for entirely different reasons. Lack of understanding in this respect is widespread among piano owners, and is responsible for an enormous amount of piano damage. A clear understanding of the difference between these two procedures is absolutely essential if the piano owner is to protect the investment in his/her piano. From the moment the factory scale designer puts pencil to paper, until the finished piano is crated and shipped, every effort is aimed at making that particular style of piano sound its musical best at one particular tone height or overall pitch. That target pitch is A-440 cycles per second, also known as American Standard Pitch. This means that the string unison "A" above middle C on your piano cycles or vibrates at the rate of 400 times each second when struck by the piano hammer. (a unison is made up two or three strings tuned exactly alike, struck by the same hammer. Almost all the notes on the piano are unison notes with the exception of a few in the low bass that sound from heavy-sound single strings.) The individual tone heights of the other eighty-seven notes are obtained with reference to "A". The overall pitch of a piano is the total overall balanced tension in pounds-pull of all of the 230 -odd strings in the instrument. For example: In a typical piano, each string, according to length, thickness, tautness, and location in the scale, exerts a calculated unit (back, plate, and tuning-pin block). The average tension or pull per string could approximate 170 pounds. When we multiply the average string tension by 230-odd strings, we come up with an overall string tension of approximately 39,100 pounds, or almost 20 tons of torsional pull within the framework of this piano. Total overall balanced string tensions vary somewhat among pianos of different stringing scales (different makes and models). It might be anywhere between 18 and 20 tons of torsional-pull. Just imagine using the tremendous pull that is trapped within the average piano to power a hoist. Such a hoist could lift forty or more heavy, old uprights all at the same time. It should now be apparent why the delicate task of lowering or raising the pitch (overall balanced string tension) of a piano is no job to entrust to an incompetent or amateur tuner. It should also be clear why "tuning quacks" seldom mention the matter of correction of pitch to a customer. It is much safer and simpler for them to tune the piano at overall pitch that already exists, take the fee, and run. Such practice allows the piano pitch to sink lower and lower, until the lack of proper overall balanced string tension results in serous structural failures in the instrument. Where lack of proper care has allowed the overall pitch to sink a quarter-tone, the loss in proper overall string tension is 1,500 to 2,500 pounds. Where overall pitch has sunk a half-tone, the loss in proper overall string tension is 3,000 to 5.000 pounds. In many older pianos that have gone without proper care for years, the loss in proper overall balanced string tension can amount to several tons. It must be remembered that when a piano is constructed, the basic structural parts (piano back, cast-iron plate, and tuning-pin block0 are engineered as a unit to remain at their structural best when holding up the correct overall pitch is lacking, parts of the piano are apt to warp, loosen, crack, split, bulge or otherwise suffer damage. This means loss in both the value and the performance of the instrument. If the damage is great and is sustained over a long period of time, (several or more years) it can render the piano worthless. Structural damage to the piano can be minimized by keeping the proper balanced overall string tension or proper overall pitch on the piano at all times. This can be accomplished only through frequent tuning to the pitch of A-440 cycles per second (American Standard Pitch). This means that you should have your piano tuned a minimum of 2 to 4 times per year as recommended by the builders of your piano. Failure by the piano owner to follow these recommendations causes failures in their piano in proportion to the total neglect. Many piano owners lack factual information regarding the above-stated needs of their pianos. But when they are aware of the truth and still neglect the care of their instruments, the fault is entirely their own. Now that you are aware of these facts of piano life, it is hoped that you will no longer believe that a piano tuner is trying to "con" you when he recommends the minimum of 2 to 4 tuning per year for any piano. His is doing you a real service! Other critically important parts of the piano, such as the soundboard, bass bridge, treble bridge, and soundboard ribbing, suffer extensive damage from loss of overall balanced string tension. For example, the average piano string (loaded with about 170 pounds of tension) also exerts a secondary force against the bridges and "crown" of the soundboard. This push amounts to about 7 pounds per string. If we multiply this by 230-odd strings, we have 1,610 pounds of pus-force against the bridges and soundboard of a piano pitched at A-440 cycles per second. To counterbalance this tremendous push-force, we have the crown of the board and the curved ribs exerting force in the opposite direction. When overall piano pitch is allowed to change too mush, the balanced forces between the strings and the bridge-soundboard combination are upset. This results in damage to the bridges, soundboard, ribbing, and associated parts. Such damage usually takes the form of warps, spits, cracks, or broken glue bonding on the bridges, soundboard, and ribs. These can be very serious failures. It should be apparent why even the most reputable of piano manufacturers and dealers cannot afford to stand behind the warranty of a piano unless the piano owner takes proper care of the instrument. In an overwhelming percentage of pitch-correction jobs the piano tuner-technician is faced with a loss in overall string tension (the pitch has dropped). But were excessive humidity has caused a formerly well-pitched sometimes happens from high summer humidity), the piano is overloaded with tension. This rise in overall string tension, if excessive, can also damage the piano. Use of a dehumidifier element installed inside the piano is highly recommended, at least during the months of highest relative humidity. In some cases it may be necessary to keep a dehumidifier in operation all year around. In the foregoing discussion we have been primarily concerned with the overall balanced string tension in the piano (overall pitch). To review, note that changes in overall piano pitch are involved with hundreds and even thousands of pounds of overall string tension. When a piano tuner-technician raises the pitch of a piano a half-tone, he is required to add from 3,000 to 5,000 pounds of overall tension. He/she is dealing in tension and not at all concerned with the sound, at that moment, except to use it as a rough guide to estimate the proper tensions. So when he/she has finished adding the correct amount of overall tension to the piano, the instrument will still be out of tune. But once the overall tension (pitch) has been corrected, the piano tuner can switch his/her primary objective to the sounds that the strings make when they are struck by the piano hammers. Until now, these sounds matted very little. Now they become all-important as the work progresses in tuning the instrument into harmony. The tuner does this by adjusting the sound or number of string vibrations of each note to an exact relationship with the same factors of all 230-odd strings. He/she is dealing in differences in sound and variations in string vibration so infinitesimal that is it impossible for the untrained ear to detect them. Your piano tuner has switched from mechanical engineer to artist. He is conceiving beauty in sound waves in relation to the human ear. He will adjust and listen intently to the sounds of every string. In so doing, he will be engaged in adjusting and making comparisons in piano string tensions, but only in infinitely small fractions of an ounce per string, and only as a byproduct of the exact sound that he must achieve. When he has finished tuning he will have 230-odd fundamental tones, each with its quota of lesser tones (partials) so arranged in harmonious relationship with one another within the framework of eighty-eight notes that only the presence of a pianist is needed to open the doors to the joys of music. It should now be clear why your piano tuner makes a separate charge for changing the pitch on a piano; it should also be apparent why he makes a separate charge for tuning a piano. A piano tuner can tune the piano at any one of a thousand incorrect pitches, and although the piano will sound in harmony with itself, the overall balanced string tension of the instrument will be all wrong, with possible disastrous consequences in ear training and piano damage. Also, a piano tuned to such an off-pitch cannot be played in tune with other fixed pitch instruments. The piano should be tuned to the correct pitch of A-440 cycles per second; but in order to tune the piano to this pitch, the correct pitch of overall balanced string tension must already be in evidence. If it is not, and the piano is basically sound enough to hold the correct overall tension, the tuner must go through the separate procedure of correcting the overall pitch before he/she can proceed to tune the instrument. Both you and your tuner will avoid a lot of headaches by following the manufactures' recommendations for frequent and regular tunings. The overall pitch will be maintained on your piano without additional costs, and you will enjoy the instrument a good deal more. Your piano tuner-technician must be capable of making overall pitch changes whenever necessary, but he is always happier when it is not necessary. In most cases he can tune another well-pitched piano in less time and with much less effort than he must expend in correcting the pitch on a badly neglected piano. After a pitch-changing session and the initial tuning, a follow-up tuning in from two to four weeks is absolutely necessary to retain the added tension (the piano will react by settling after the first session). If the piano is allowed to settle too long before the follow-up tuning, another pitch-raising session (at additional cost) will be required. |
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