Why does your piano need tuning?

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At standard pitch, A 440 Hz, there is a tremendous amount of stress placed on the piano. This is due to the high tension of the approximate 230 strings. The overall tension on the piano is about 18 - 20 tons!  In addition to all of this stress, there are many contributing factors which cause a piano to go "out of tune".  Following are just a few of the many contributing factors:

Humidity and Temperature:

One of the biggest factors which cause a piano to go out of tune is the changes in climate. The strings are stretched across the soundboard, which is made out of wood. When conditions are too humid, wood takes on moisture and expands.   As the piano's soundboard takes on moisture, it swells, producing an upward bulge.  Through the bridge, this puts additional tension on the strings.  Thus, the pitch is too high, or sharp, in the lower mid-range and high treble sections.  Also important to know, is that the strings in your piano are held tight by pins in a pinblock.  As the pinblock absorbs moisture in high humidity situations, it swells, crushing the wood fibers against the pins.

When the air dries out, so does the soundboard. In dry conditions, the soundboard shrinks and will flatten.  The tension of the strings over the bridge becomes inadequate and the pitch of the mid-range and treble sections becomes flat, or under pitch.

Every change in humidity causes the pitch to rise or fall. Therefore, with every fluctuation in humidity the piano gradually goes out of tune. The more constant the humidity the better a piano will stay in tune. Changes in temperature and direct sunlight, also have an effect on the pitch of a piano.

Stretching of Strings:

Another factor which affects the tuning stability of a new or recently restrung piano, is the tendency of new wire to stretch when it is under stress.  Until the wire it stretched and termination points are well defined, a new piano or newly restrung piano will require frequent tunings.  Most manufacturers recommend 2-4 tunings the first several years.

Slipping Tuning Pins:

Older pianos may not stay in tune as well as they should if the pin block dries out too much. The tuning pins are driven into the holes of the wood pin block and it is this friction that keeps them from turning when under the high tension of the tuned strings. In pianos that have been exposed to extremely dry conditions and frequent and extreme swings in humidity and temperature, the pin block eventually becomes so dry that it shrinks and the holes are enlarged so that the pins start to slip. If this happens, a piano will go out of tune very quickly. Driving in the tuning pins or replacing the tuning pins with a larger diameter pin usually improves the tuning stability of the piano. In some cases, the entire pin block may need restored or even replaced.

My Suggestions:

Maintain a constant environment for your piano. Ideally, the relative humidity level should be between 40 and 45 % and without excessively warm or cool temperatures, ideally around 62-68 degrees. If possible, place the piano on an interior wall and away from all heat sources and away from direct sun light. Also, avoid any drafts, such as those caused by older windows and areas near a doorway. If you want to protect your investment, consider having a Dampp-Chaser Piano Life Saver System installed on your piano.  The system will monitor the humidity levels around your piano and humidify and dehumidify as needed. If you use a room humidifier, DO NOT place it directly under a grand piano or under the key-bed of an upright piano. The direct airflow and moisture output of most room humidifiers could damage your piano, rather than help it. Rather, simply place it in the general vicinity of your piano, purchase a hygrometer, and closely monitor the humidity levels. Adjust the humidifier as needed in order to achieve the optimal level of humidity.

Please don't hesitate to give me a call or email to discuss and questions and/or concerns regarding any of the above information. 

(717) 817-7810 or Email