Schedule an Appointment

(800) 738-8633 (800) RE-TUNED

The Largest Piano Tuning and Service Organization in the Western United States Exceeding Your Expectations Since 1976

  • An association of piano technicians, working under the guidance of Shawn Skylark, a highly acclaimed concert tuner with over 36 years of experience
  • The only piano service to offer a money-back, 100% satisfaction guarantee
  • Whatever type of piano you have, whatever level of service you require, we have the right technician for you!
  • 1a
  • 2a
  • 3a
  • 1a
  • 2a
  • 3a
  • 1a
  • 2a
  • 3a
  • 1a
  • 2a
  • 3a

Why Do Pianos Go Out of Tune?

One of the most common questions we are asked is "Does my piano need tuning if no one is playing it? Why does it go out of tune?"

The answer is yes, pianos go out of tune for a variety or reasons, depending on the specific circumstances. Lets start with a quick summary, and then look at each reason in more detail. Pianos go out of tune because:

  1. The strings stretch
  2. Temperature and humidity changes
  3. Poor tuning technique
  4. Normal use
  5. The piano is moved

1. The Strings Stretch

New pianos, or pianos with new strings go out of tune quickly, and often dramatically.

A piano string is a piece of steel wire. Even so, it will stretch, like a very stiff rubber band when tightened. It is designed to stretch significantly, and still not break when at its correct pitch.

Imagine a piano wire tied to a hook on the ceiling, and then imagine a 200lb. weight attached to the string at the bottom. Measure the distance from the weight to the floor every morning. Each day you will find that the string is a little close to the floor; it is slowly stretching.

Eventually it will stop. At that point we have what we call a "stable" wire. In other words, at any given tension a string will stretch, but unless it is stretched beyond its "elastic limit" it will not stretch forever; it will reach a stable equilibrium. As long as the tension remains constant the string will stop stretching.

When a piano is tuned, it is designed so that each string will in fact be tightened the equivalent of approximately 200 lbs., in order to achieve the desired frequency. So, the first time a piano is tuned, the strings are tightened, but they immediately begin to stretch.

Since they cannot in fact get longer, as in our example, they just "sag" instead; that is, they drop in frequency, and very quickly the first few times. As they sag, the tension is reduced so they continue to stretch but more slowly, until they "stabilize," but at the wrong tension!

So, the tuner comes along and tightens the strings again, and they start stretching again, each time a little more slowly and a little less drastically, but the process continues, usually at least for six to eight tunings, on average. This is why it is so important to tune new pianos more frequently. We are trying to get through this unstable "stretching" phase to bring the strings to a place where they at least will be capable of staying in tune.

2. Temperature And Humidity Changes

When the string is struck by the hammer the vibration it produces is in fact very quiet, because it cannot move a lot of air, which is how sound travels. So we need to amplify the sound acoustically.

Early instrument makers discovered that planks of wood, when put under tension, would very effectively reproduce and amplify vibrations. In pianos that wood is called the sound board, or sounding board. A long wooden "rail" (the bridge) is attached to the sound board, and the vibrating strings pass over that bridge, in such a way as to be pressing down slightly on it. (This is known as the "down-bearing.) Thus, when the string vibrates it transfers that vibration to the soundboard via the bridge.

The sound board, however, must be free to vibrate, so except for the rim where it is attached to the piano cabinet, it hangs in the air, waiting to receive the "signal" from the piano strings.

Now, all wood has a certain amount of moisture in it. If it is exposed to air that has LESS moisture, it will gradually tend to loose its moisture until it equalizes with its environment. Similarly, it will take in moisture in a damp environment. Of course, the moisture in the air (humidity), is constantly changing. As a result, the sound board is also constantly changing, as it tries to stay in equilibrium with its environment.

The sound board is restrained form expanding or contracting at the sides of the cabinet, as it is permanently fixed with glue and screws. When first placed in the piano, the sound board is arched upward in order to create tension in the wood. This is called its "crown." When the board picks up moisture, it has nowhere to go but up! The arch will increase as the boards swells. Likewise it will drop as the moisture is released.

Every time the board moves up or down, it makes the strings that are resting on it (via the bridge) tighter or looser, and not necessarily uniformly. Thus, every time the board moves due to changing humidity, the tension on the wires changes and the strings go out of tune.

If the strings are stable as explained above, AND have been properly "set," it is very possible for the piano to go out of tune, and then BACK into tune if the board returns to the humidity level it was at during the last tuning!

Even if the piano is never played, the process of pushing and releasing the strings will constantly change the tuning. It will also cause the pins that hold the wires to move, and once again leave the strings out of tune. This is why it is so important to TRY to maintain a temperature and humidity level that is as constant as possible. The location of the piano can dramatically affect it's ability to stay in tune.

When it is too difficult to do so, it is time to consider installing a Dampp-Chaser system and string cover to help create a more stable "micro climate."

3. Poor Tuning Technique

The string has not been "set."

All pianos are designed differently, but this is a general description of the journey a piano string makes from front to back. The piano string begins at the tuning pin, then: rests on hard felt, is pressed against one or two metal "frets," then hangs in space until it reaches the top of a wooden rail (the bridge) where it slides against two pins and across the bridge top, then slides across another metal "fret" until reaching the rear "hitch" pin.

Usually, it then wraps around that pin and makes the same journey back to the next tuning pin. In other words, one piece of wire actually creates two independent strings, which have A LOT of places where friction occurs as it is being pulled.

You could imagine each little portion of the string that exists between any of the friction points, and imagine that there might be some way to measure the tension in just that little section. As the string is tightened and loosened during the tuning process it must slide equally along all of its friction points. Otherwise, even if the frequency sounds perfect when the tuner finishes, the string may be left with one portion under slightly different tension than another.

It's like trying to pull a garden hose that is "hung up" on a sprinkler or a rock. You pull harder, so that the part of the hose between your hands and the rock is a lot tighter than the part past the rock, until it finally breaks free.

So what do you do when the garden hose IS stuck? You give it a good hard SHAKE, right? Same with tuning. It is important that the tuner hits the strings pretty hard while turning the pin, so that the string has less chance of getting "stuck." This hard "test blow" is a technique that many inexperienced tuners may not use, but is critical to achieving a stable result.

When the pianist plays and hits the string, eventually the string will "shake itself" free where it might have been a little stuck, and when it does the tension on the whole wire will change slightly. It is the tuners job to do everything possible to make sure that the string tension is as even and equal as possible.

(A string that is rusty or has been sitting for years untuned and in the "wrong" place presents a challenge to even the most experiences tuner. Trying to get such a string to "slide" smoothly across its friction points as it is being pulled is almost impossible, presenting another reason to keep pianos tuned more regularly, and address problems that are causing the strings to rust, corrode, or deteriorate.)

Still, in their attempt to find the right frequency, an inexperienced tuner can tighten and loosen a string much more drastically than necessary. When this happens it is virtually impossible to leave an equalized or "set" string. Thus, poor tuning technique is clearly one possible reason why the string is not set and will move and go out of tune.

However, even the best tuner cannot overcome the laws of physics. The farther (in frequency) the string is when it starts from where it needs to be, the more the tuner must turn the pin, and the more challenging it becomes to properly set the string. This is another reason why regular tuning is recommended: so that the piano is out of tune enough to make paying for tuning justified, but not so far out as to make it difficult or impossible to leave it in an ideal, stable condition.

The pin has not been "set."

Just like the strings on a guitar are wrapped around a peg that is turned when tuning, the strings on a piano are wrapped around a metal pin that fits tightly into a hard wooden block (the pin block.) Even if, as described above, the tension has been properly equalized, turning the tuning pin itself is also a challenge.

Although it is made of steel, the tuning pin can bend slightly from front to back as it is being manipulated. Also, it can twist in a rotating motion without actually turning in the wood. When either of these events happens, the pin itself is left in an unstable situation, which it may not immediately correct on its own. Eventually, as before, the string is struck and the force transferred to the pin causes the pin to correct itself and move to a stabilized position. When the pin moves, it moves the string and puts it out of tune.

Once again, the inexperienced tuner can fail to "set" the pin properly, thus allowing the string to change when it is played. And also as above, the more a tuner needs to turn the pin, the harder it is to set.

4. Normal Use

Even the best efforts of a "top" technician cannot last forever. The more a string is struck and the harder it is struck the more likely it is that it will cause the tuning pin to turn slightly and put the string out of tune again. This is why professional players usually have their pianos tuned more frequently than average.

Most teachers and performers tune their high-end instruments at least three or four times per year, and sometimes more often than that. If you play hard on any piano for many hours every day, it just won't stay in tune as well. It is my experience that pianos with extremely tight tuning pins are much harder to stabilize initially, but that once they ARE stable they will tend to stay in tune better under hard use simply because it takes more force to move the pin.

5. The piano is moved

Although moving a piano, either across a room or across the state will affect the tuning, this is often not as significant as the reasons above. When it is moved the resting position of the soundboard can be disturbed, changing the string tension.

The more it is "bounced around" the more it may cause the pins to turn slightly. If it is moved to a location with different average humidity, the piano will try to reestablish equilibrium and go out of tune for the reasons explained above.

So, although moving a piano can clearly disturb the tuning, it is often not as dramatic as commonly believed.

We Specialize in:
  • Bosendorfer
  • Steinway
  • Petrof
  • Schimmel
  • Yamaha