Piano Tuning, Regulation, Repair, Rebuilding
Why Do Pianos Go Out of Tune?
First and foremost, every piano owner and player should understand this most inescapable fact:
The very minute the piano tuner walks out the door your piano begins its slow but inexorable process of going out of tune.
That’s just the nature of the beast. The piano is an incredibly complex musical instrument with myriad parts and pieces and hundreds of strings under immense tension (read more below). The piano is “alive” with energy even as it sits idle. Add to that environmental conditions and voila—you’ve got chaos... subtle in most cases—but chaos nonetheless.
That’s why concert and recording studio pianos are tuned regularly and immediately prior to each performance. No master pianist would consider performing on a piano that hadn’t been tuned to perfection just prior to the performance.
However, in the main, most pianos will sound reasonably good for up to six months after tuning, but by about this time nature has taken her course and the piano is due for another tuning. We especially recommend that your piano be tuned every six months if 1) anyone is currently learning on the instrument and/or 2) you play it a great deal. Don’t wait too long to get it tuned… you deserve to play and hear your instrument at its best. Moreover, if you wait too long the piano might require a pitch raise and any money saved waiting to have it tuned will go towards that.
The piano's strings are under a great deal of tension—on average, about 168lbs per string—and with about 220 strings in the typical piano that equates to quite a bit of tension across the piano—nearly 20 tons!
The biggest impact on a piano's pitch and tuning is, quite simply, humidity. The tension force from the strings is distributed across the plate and frame, over the bridges and against the soundboard. The soundboard and bridges are most susceptible. Made of wood, usually high quality spruce, moisture in the air seeps in and out with the changes in humidity.
It’s important to keep your piano in tune. It was designed to work best when tuned to the International Pitch Standard of A440 (the A just above Middle C should vibrate at 440Hz). Your piano will sound its best and give you and your family the most pleasure when it is tuned regularly and kept in proper playing condition.
How often should my piano be serviced?
©1993 Piano Technicians Guild
Your piano is an investment in your future. It can bring you and your family a lifetime of music, adding immeasurable joy and beauty to your home. Since it is also such a large investment, it should be maintained with the utmost care. Regular servicing by a qualified technician will preserve your instrument and help you avoid costly repairs in the future.
Because your piano contains materials such as wood and felt, it is subject to change with climatic conditions. Extreme swings from hot to cold or dry to wet cause its materials to swell and contract, affecting tone, pitch, and action response or touch. You can reduce the severity of these effects by placing your piano near a wall away from windows or doors that are opened frequently. Avoid heating and air conditioning vents, fireplaces and areas which receive direct sunlight. Your piano will perform best under consistent conditions neither too wet nor dry, optimally at a temperature of 68 degrees F and 42 percent relative humidity.
While pianos generally fall into vertical and grand model categories, each manufacturer selects its own materials and utilizes its own unique scale and furniture designs. Every piano requires a different level of maintenance, depending upon the quality of materials used and the design and level of craftsmanship. Manufacturers can provide general advice on tuning frequency but your technician can give specific recommendations based upon your usage and locale. Most major piano manufacturers recommend tuning their pianos two to four times per year at a minimum.
The preceding article is a reprint of a Technical Bulletin published by the Piano Technicians Guild, Inc. Piano Technicians Guild is an international organization of piano technicians. Registered Piano Technicians (RPTs) are those members who have passed a series of examinations on the maintenance, repair, and tuning of pianos.
How Often Should You Service Your Piano?
If you are serious about purchasing a new or used piano, the very best advice we can give you is this:
Read Larry Fine’s book on the subject, “The Piano Book – Buying & Owning a New or Used Piano.”
You should be able to find it at most bookstores and you can usually find it for rent at your local library. It is well worth reading.
At over 244 pages it covers just about everything you need to know: the various piano manufacturers, piano design and nomenclature, how pianos work, what to look for in a used piano, what to check for in a new piano. It lists most of the major piano manufacturers and gives you a little history on each. It also rates the individual manufacturers on things like performance, quality, and service.
We can't come close to the level of detail provided in “The Piano Book” on this website, but we’d be happy to answer any question you might have about purchasing a new or used piano. Or if you’d like a used piano evaluated, we’d be happy to do that too. Feel free to call us at 540.878.0000 or send an email to firstname.lastname@example.org.
© 2009 Amadeus Piano Co. All rights reserved.
In the summer, when the air becomes humid, the soundboard swells, and in so doing, places tension against the strings, causing them to go sharp. In the dry winter the opposite happens, the soundboard dries and contracts, causing the strings to relax just a bit, and the piano goes flat; and because the piano is so complex, this process is nothing if not chaotic.
As you might imagine, the soundboard and bridges probably don't swell and contract in any uniform way. Fine soundboards (and pianos), like living things, tend to behave in an erratic manner. So you’ll find that not only does the piano go flat or sharp, depending on the season, it does so in an inconsistent way, i.e., the unisons go "out" (the two or three strings per note). These notes sound twangy and discordant, and no one wants to play a discordant piano.
Temperature itself can have an impact on pitch and tuning stability, but for the most part only in cases where we see dramatic shifts in room temperature over short periods of time, and in cases where the piano sits in direct sunlight, absorbing a great deal of radiant heat, or near a heating or air-conditioning vent. If the room in which the piano sits changes in temperature, going from cold, say, to warm after turning the heat on, for example, the piano’s pitch will be affected—in this case, the warming of the piano wire, soundboard, and bridges, will cause the piano to drop in pitch a bit. And, subsequently, when the room cools again, the piano will rise in pitch a few cents (a few hundredths of a semitone).
There are other things that can influence piano pitch and tuning, but to a lesser degree. For example, new strings go out of tune quickly until they are stabilized—a process that takes several tunings over a long period. It is recommended that you have your new piano tuned at least four times the first year and two to three times a year for the next two or three years. The same rule applies to newly strung (or restrung) pianos. New piano wire is highly elastic and takes time to settle in.
And lastly, mechanical failure can, of course, cause all sorts of problems. Loose tuning pins, for example, will naturally cause problems with tuning stability.
Copyright © 2009 Amadeus Piano Co. All rights reserved.
Except where otherwise indicated, All Copyright © 2009 Amadeus Piano Co. All rights reserved.
What is a Cent?
One CENT = 1/100 of a semitone. 100 CENTS = 1 semitone. (1 semitone is the span (interval) from note to note on the piano).
E.g., if a piano is 100 cents flat (wildly off pitch), middle C actually sounds like what the B below it is supposed to sound like, and that B sounds like what the A# below it should sound like, etc. throughout the keyboard. It makes it impossible to play the piano with other instruments and makes the piano sound dull and lifeless (it was designed to be tuned to A440).
It's particularly important that any piano used for lessons be tuned to the proper pitch. Learning to play on a flat or off-pitch piano is like learning to read using misspelled words. You can do it… but as the reader finds himself lost when he comes to a correctly spelled book, so the piano student is bewildered when she comes to a properly tuned piano.
Copyright © 2009 Amadeus Piano Co. All rights reserved.
In order for a piano to function properly the geometry of the action, everything from the key to the hammer, (see diagram below) has to be just right, the precise ratio of the distance the key travels downward to the distance the hammer travels up toward the strings and back again, and all the bits in between.
There are over seventy unique and identifiable parts for each key in a piano action, grand or upright; that’s over six thousand total in the complete action! Most of these parts are adjustable and by turning screws, adjusting springs, bending wires, and tweaking the depth of the felt and cloth cushions and paper shims, we regulate (or adjust and fine-tune) the geometry of the action so that the piano performs well.
What is Piano Regulation?
When you depress a key on the piano a complex chain of events are set into motion: first, the capstan (42) pushes on the wippen (24) (the base of the escapement mechanism), the wippen pushes the jack (31) (looks like a boot, it's the whole piece shaped like an "L"), the jack is pushed up through a slot (you can't see in the diagram) in the repletion lever (19) and pushes the hammer knuckle (20) and the hammer (6) begins moving upward. When the hammer is about half-way to the strings, the back end of the key pushes on the damper lever (36) and the damper (3) begins to lift off the strings. As the front end of the key continues down and the hammer has almost reached the strings, the jack toe contacts the letoff button (29) and the jack slips out from under the knuckle (imagine the jack moving upward and contacting the letoff button which forces the top of the jack toward the front (right in the diagram) so that the jack is no longer pushing on the hammer knuckle but rather slides just forward of it). When the hammer rebounds, and because the jack has been “tripped” out from under the knuckle, the knuckle now lands on the repetition lever (19), not on the jack (remember, there’s a slot/hole in the rep lever that the jack end travels through). During normal play, the force of the hammer shaft (7) is stronger than the repetition lever spring (23) and the hammer continues down until it is caught by the backcheck (15) where it remains while the key is pushed down.
At this moment in time, while the key is still pressed down, the damper is still lifted, the hammer has bounced off the strings and is now held in place by the backcheck, the jack is out from under the hammer knuckle (20) having been tripped by the letoff button and the repetition lever is in the down and “cocked” position. The rep lever spring is strong enough to lift the hammer, but it can't because the hammer tail is being held in position by the backcheck. (Visualize the front of the key pressed down, the rear of the key (and the backcheck) raised, the hammer tail caught in the backcheck, the wippen raised, with the rep lever squeezed down between the hammer knuckle and the wippen and in the “cocked” position, its energy derived from the spring).
As the key is released, the backcheck disengages from the hammer tail and the rep lever (with its spring) pushes the hammer up until it (the rep lever) engages the drop screw. And as the back of the key continues to go down, so the wippen goes down and the jack follows and pivots back under the hammer knuckle as it (the jack) disengages from the letoff button. The jack clears the letoff button when the front end of the key is less than half-way up and the action is now ready for another complete cycle without needing the key to return all the way to its rest (beginning) position. Once the key is completely released, the damper falls and mutes the strings.
(In a vertical/upright action it works a bit differently, one has to release the key completely in order to repeat the note; that’s why it’s easier to repeat notes quickly on a grand than on a vertical).
All of this happens in the wink of an eye. And that’s just the beginning. There are myriad other bits and pieces we haven’t touched on.
The tolerances in much of the action are exceptionally narrow and we measure widths between working parts down to .003”and travel as little as 1/32 of an inch, and we fine-tune key movement even smaller—tissue thin distances can impact the feel and performance of the key as it is played. It’s critical that everything lines up just right, that everything happens when and as it’s supposed to, and it’s important that each key behaves as it should and that all the keys behave similarly from the pianist point of view. And because a piano’s action is made up of natural materials (wood, felt, leather, and even paper for spacers) over time, these materials wear, warp, or breakdown.
It doesn’t take much to change the geometry of the action—hammer wear, felt wear, loose screws, wood swelling or warping, etc.—which in turn results in unpredictable behavior or even catastrophic failure if left unchecked. In the best case scenario, your action might begin to feel “different.” It might become sluggish or less responsive, or “slippery” and unruly, or you might sense some diminished control; playing becomes exhausting.
And over time, the specific geometry of the action works its way out of regulation. It takes several years but it happens on all pianos—that's just the nature of the beast. The complex series of levers no longer work precisely and in the worst cases, you get things like hammers "blocking" against the strings, or just as bad, "bouncing" against the strings, or notes not repeating—making it nearly impossible to play the piano.
The general recommendation is that you have your piano's action regulated at least every 8 - 10 years, or as needed; a little more often for hard or frequent play, a little less often for pianos that don't get much play. This ensures everything is in proper working order; old or worn parts are replaced; all the proper adjustments are made to compensate for wear and use. If you play a lot and haven’t had the piano’s action regulated within the last five to ten years, we can almost guarantee you that it’s not performing as well as it could be.
We go through a 25 step process for each of the 88 keys in the action. We check everything from how well the key frame sits in the piano to how well the hammers line and match up to the strings. We level, square, and space the keys; we regulate the key dip, the jack to knuckle alignment, the rep lever height, the hammer height, the letoff, the hammer drop, the backchecks, the dampers; and we align the wippens, and check the repetition spring tension; we regulate the pedals. Our process is meticulous and comprehensive. You can be assured that when we are done, your action is to spec and performing to its potential.
Copyright © 2009 Amadeus Piano Co. All rights reserved.
The Anatomy of a Keystroke: