Why Do Pianos Go Out of Tune?
How To Keep Your Piano in Tune
Humidity Control Devices
Why Pianos Go Out of Tune
There are several factors that can alter the tuning of a piano: humidity, temperature, moving, excessively hard playing, aged or worn materials, and abuse. Humidity fluctuations is the number one cause of changes in piano tuning. When the soundboard, pinblock and bridge are in a moist environment, the wood cells absorb the moisture and swell up, and as they expand they pull the strings tighter, causing the piano to go sharp. Logically, if the piano moves to a drier atmosphere, the wood shrinks, the strings loosen and go flat, and sometimes cracks and splits may open and start buzzing. Every seasonal change — every wet season and dry season — alters a piano’s tuning, and on a smaller scale.
Temperature is somewhat related to humidity. When the steel strings heat up, they loosen and go flat. When they get cold, they tighten and the piano goes sharp. Every winter and summer, day and night, wood stove crackling or doors and windows wide open, the temperature is in constant flux. A piano on stage in an auditorium or sitting in a church spends all week in a cold environment, until Sunday or the evening of the concert when the heat is turned on, the hot stage lights shine down and the warm audience enters and breathes hot humid air into the room. The tuning makes a major shift.
Moving always knocks a piano out of tune. The position of the tuning pins in the pinblock and the wires over the bridge pins is quite sensitive. Any time a piano is tilted or jostled, there is bound to be a shift in these positions. If a piano is moved from one environment to another, then there may also be a change in humidity and temperature.
Excessively hard playing causes a piano to go out of tune when the force of the hammer is strong enough actually to stretch the speaking length of the string enough to pull it over the friction points.
Many materials can become aged or worn. Those specifically related to tuning stability are generally wood, although some metal parts can give as well. In particular, the pinblock can become split, or the tuning pins can become loose in their holes from repeated tunings or wood shrinkage. The bridges can split, usually along the line of the bridge pins; as the strings are tightened during tuning, the pins then move and do not keep the piano wire in place. Sometimes V-bars, agraffes, and hitch pins can bend or move as well.
Abuse of the piano or the tuning can also be a cause of a piano’s going out of tune; avoiding abuse is common sense for proper piano care and maintenance.
How To Keep Your Piano In Tune
There are three key ingredients for keeping a piano in tune: location, humidity control and frequent tuning. Location is important. The ideal situation for a piano is a room with constant temperature and humidity. Avoid proximity to frequently open doors and windows, to heaters and fireplaces, to the steam from kitchens and bathrooms, and direct exposure to the sun.
Humidity control is now a realistic possibility almost regardless of location. Since it is not always practical to keep a room or a large space heated or dry, it makes sense and “cents” to localize the treatment. A covered piano equipped with a humidity-control device will hold its tune remarkably well. (For more on relative humidity, click here.)
Frequent tuning assures the player of hearing proper sounds. The more often a piano is tuned, the smaller are the adjustments that need to be made each time. The smaller the adjustments, the more stable the tuning will be. The more stable the tuning, the longer it will last. Tune at least twice a year, or every significant weather change. Concert pianos are tuned before every concert, sometimes weekly or daily, just as violins and guitars are tuned before each performance.
Humidity Control Devices
Sticking drawers, sticking doors and loose furniture joints all change with the weather and the seasons. In the summertime when humidity levels in the air are higher, wood absorbs this moisture and swells. In the winter when the air becomes dryer from winter heating and lued wooden joints become loose and wobbly. Just as doors and drawers become tight withhigh humidity and loose in dry air, the keys of your piano may stick down when struck in times of high humidity. When the environment surrounding your piano is dry the keys may seem to rattle when played. As you play your piano, you will notice how responsive the keys are to your touch. The way the keys cause the wood hammers to strike the piano strings is apart of thousands of interconnectred wooden parts called the piano action. With high moisture levels in the piano action, the action is sluggish, and the keys seem non-responsive to your touch. The soundboard is the single largest piece of wood in your piano. It actually vibrates to amplify the sound produced by the strings. The bridges of your piano are joined to the soundboard and support the strings. As the soundboard absorbs moisture from the air surrounding the piano, it swells, producing an upward bulge. Through the bridge, this puts additional tension on the strings. Now the pitch is too high in the lower mid-range and extreme treble strings. When the soundboard shrinks and flattens, the tebnsion of strings over the bridge becomes inadequate. The pitch of the mid-range and treble strings is now flat. Over time, constant changes in humidity levels, with the corresponding shrinking and swelling of the soundboard, will damage the integrity of the soundboard. You will see this damage in the form of a crack in the soundboard. The strings of your piano are held tight by the pins in the pinblock. As the pinblock absorbs moisture in periods of high humidity, it swells, crushing the wood fibers against the pin. In dry periods, the wood shrinks away from the pin, loosening it and causing the string to sag. When this cycle is repeated time after time, the wood fibers surrounding the pin are destroyed and lose their resilience. With continuous swelling and shrinking, the wood can no longer provide the snug fit required to hold pins in place. The strings of your piano are responsible for producing the musical sounds. With exposure to high humidity levels over long periods, strings become rusted and corroded. At the junction where rusted strings wrap around rusted pins, rust corrosion forms a hardened bond between the two. Then, during a tunig, when your piano technician turns the pins to stretch the strings, the inflexible rusted string snaps at this joint.
The Dampp-Chaser Climate Control System maintains your piano at an average 42% relative humidity as recommended by major piano manufactureres. Then your piano soundboard is kept at a constant moisture level, shrinking and swelling are minimized. Your piano goes out of tune when the humidity levels in your home environment are controlled to some extent by the temperature. Generally, an air conditioner will remove some summer humidity, but the drop in humidity, when winter dryness sets, in, presents a significant moisture change which will put your piano out of tune. When your piano is maintained at 42% relative humidity, it will stay in tune longer and better. The Dampp-Chaser Climate Control System is made up of three basic components whcih work together to control the humidity levels within your piano, maintaining the recommended 42% relative humidity, no matter what the external conditions are.
- Humidistat – this is the brain of the system, which senses whether the wooden parts of your piano are too moist or too dry.
- Dehumidifier – carries moisture away from your piano using air currents when humidity levels rise.
- Humidifier – moisturizes the dry wood of your piano when the humidity drops below 42%.
How it works These components cycle together to maintain the wood of your piano at 42% relative humidity. When the humidistat, located less than an inch from your soundboard, senses that the wood is dry, it turns the power on the humidifier. Then, when the humidifier has provided enough moisture to the soundboard, the humidistat turns off the humidifier and turns the power on to the dehumidifier. The dehumidifier carres away moisture from the soundboard on air currents until the humidistat again senses that the soundboard is dry. The system again switchews to the humidifying function. The cycle continues day after day, year after year, protcting your piano from external conditions. The system must be installed by a qualified piano technician. Only your technician can be sure that each component is located for optimal effectiveness and protection. Each Dampp-Chaser System carries a 5-year guarantee. The early 20th century saw peak production of pianos as economic prosperity permitted many families to own a piano. Thousands of those vintage pianos survived the years and are now being restored to their original condition. Today, leading piano remanufacturers strongly recommend the installation of a Dampp-Chase Climate Control System to prevent continued wood cell deterieoration and metal erosion in the older piano. The System is installed out-of-sight in your piano, maintaining the same environment now provided for the treasured pianos on display in the Smithsonian Institue. If you value your piano, it is well worth installing a humidity-control device. Order your humidity control device now!
By the way, if it has been longer than six months, your piano is probable ready for a tuning. It is a good idea to schedule each subsequent tuning the day your current tuning is happening. Plan ahead, get on a regular tuning schedule, and know that your piano will be well maintained far into the future.
If you wait too long, your piano may look like this: