Golden Piano Tuning - Columbus Ohio

What Makes a Piano Go Out of Tune?

Golden Piano Tuning, Columbus Ohio

In Billl’s 30+ years of tuning thousands of pianos, he has encountered all types of piano “personalities” as related to tunings and tuning stability. Some pianos, maintained on either a 6 months or annual basis, remain quite stable (+/- 1 to 3 cents) while other pianos go sharp or flat anywhere between 10 and 20 cents each visit. It is also important to note that pianos do not go flat or sharp uniformly. Some strings will invariably change more than others.

Have you ever wondered what makes a piano go out of tune? Here are some of the things that cause pianos to go out of tune.


Piano is not built well or of quality materials – As poor quality pianos age, they may tend to not hold their tune as well as when they were new and this instability condition will appear sooner in the piano’s life than with high quality pianos.

The piano has not been tuned on a regular basis – Every piano manufacturer recommends tuning on a 6 month schedule (some even recommend tuning every 3 months). In any case, a piano should never go more than 1 year without being tuned. If a piano is tuned less frequently, it may take years to stabilize, if at all.  Pianos that are not tuned every 6 months are more prone to stability problems because the tuning pins, strings, etc. are not acclimated or conditioned to where they need to be.

The tuning pins don’t hold the strings well – This will result in strings that move around a bit in-between tunings. If the tuning pin is in what I call the “slightly soft” to “soft” category, this movement can begin in a matter of days or even hours. This condition can exist whether or not the piano is tuned on a regular basis.

The humidity changed – Humidity changes all the time, but most significantly when the seasons change. Winter humidity can drop into the upper teens in some homes and in the summer can rise into the 60% range. That is a significant change in humidity.

Windows open on regular basis – If you like to keep your windows open at home to bring in all that fresh (and typically humid) air, you risk causing the piano to go out of tune more quickly. Pianos like to be stable at 42%, and if that is not possible, pianos like the temperature and humidity to be as constant as possible.

I open my windows during warmer weather – If you open your windows to air out your house with fresh and usually humid air, you are a prime candidate for regular piano tunings. When the soundboard, pin block, and bridge are in a humid environment (ideal is 42%, above 60% would be considered humid), the wood cells absorb the moisture and swell up, and as they expand they pull the strings tighter, causing the piano to go sharp.

The pianist plays very forcefully – 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.

The piano is old – Older piano components specifically related to tuning stability are generally made of wood, although some metal parts can degrade as well.  In particular, the pin block 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. Any of these events can lead to a less-stable piano tuning.

It’s a grand piano and the lid is up – When a grand piano lid is kept in the up position, your piano strings constant exposure to the ever-changing temperature and humidity in your home and therefore will react more quickly and dramatically to temperature and humidity fluctuations.

The piano has been moved – Moving always knocks a piano out of tune.  The position of the tuning pins in the pin block 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.


Dr. William Braid White, in his book, Piano Tuning and Allied Arts, says, “In order to understand why a piano goes out of tune, it is first necessary to remember that the whole instrument is always under a varying stress. The two-hundred-and-thirty odd strings are stretched at average tensions of from one hundred and fifty to two hundred pounds apiece; so that the iron plate, together with the heavy wooden framing carries a strain totaling from eighteen to twenty tons.

Now, this stress is not constant, for the reason that the steel wire is highly elastic. The soundboard is merely a thin sheet of spruce wood averaging three-eighths of an inch in thickness. If it be properly constructed, the whole board becomes something like a highly elastic spring. The more elastic it is, the freer and more agreeable will be the tone emanating from the piano.

From a strictly scientific point of view, it is probably true to say that no piano ever made has stood in tune, without a drop or a rise for more than twenty-four hours, unless it were maintained at constant temperature, and under constant barometric and hygroscopic conditions in a laboratory.”

Stories are told of piano owners, in an attempt to avoid having their pianos tuned, tried both soldering and epoxying their tuning pins to lock them in place, presuming that tuning pin movement is the only thing that caused pianos to go out of tune. Those were very bad presumptions that were very expensive to repair. Do not try this at home! 🙂