Tuning – Why does a Piano have to be tuned?

The question comes up from time to time, why does the piano go out of tune so frequently? A piano is constructed mostly of wood and metal parts. A piano is like a harp. Strings, which are highly elastic and have a tension of 13 to 20 tons are strung over bridges which transfer sound to the sounding board. In the majority of pianos this board is three-eights of an inch thick spruce making it elastic also. When the climatic conditions change (which in Canada happens from one day to the next), this board moves. When it is very damp the board swells and in cold dry weather the board shrinks. The strings will become slack from this constant shifting and the pitch will drop. No piano will stay in tune for more than 24 hours unless it is in the most perfect climatic environment. The tuning pins, the wooden frame and the iron plate that supports this construction will only suffer if the piano is not serviced regularly. The long term effects of neglect may cause cracking and other major difficulties and eventually cause the piano to become totally beyond repair.

Out of Tune Vs. Out of Pitch

Because the soundboard, bridge work, pin block and other related wooden parts swell in humid hot weather and shrink in dry cold weather, the pitch and tuning stability is very easily affected. In the high humidity the pitch tends to sharpen and in dryer weather the pitch tends to flatten. This change can be as much as a quarter, half or a semi-tone either way. This is quite a strain on the instrument considering that at normal pitch the average piano has about 13 tons of tension on it to start with. Such changes can cause the pitch to drop drastically from one year to the next. If the instrument is left untuned, it can develop loose tuning pins because of the continued slackening of the strings. Other repair problems can occur in the sound producing parts as well as the action. The piano may sound relatively in tune with itself to some degree; however, it could be drastically out of pitch. To avoid this condition the instrument must be tuned whether it is played or not. So to protect the investment you have in your piano, you should tune it regularly at the same time reducing the cost of major repairs. The National Association on Piano Manufacturers recommends tuning your piano once every season change or at least every six months and not less than once per year. They also recommend action regulation, cleaning and tightening every few years as required. New pianos should be tuned four times the first year to stabilize tuning because new wire is very elastic and tuning pin torques very tight. You can check your humidity with a digital hygrometer which is available at most department stores, Pianos operate best at between 40 to 60% humidity at say 70 degrees fahrenheit. Your tuner will inform you if there are any serious humidity problems with your instrument. However, if you find your piano doesn’t stay in tune even shortly after it is tuned, perhaps there has been a change and some precautions should be taken such as installing a piano dehumidifier or a humidifier. Humidity can cause numerous other problems besides tuning. It causes rusty strings (which can break very easily), rusty tuning, action and bridge pins, also sluggish keys and action parts. Dryness on the other hand can cause loose keys and action, also loose tuning and bridge pins. There are about 4,000 parts per piano that may be affected. Do not place piano’s near heat registers or direct sun light.

The Action

In the action, we again have mostly wooden and metal parts. Under the same climatic changes they also shrink and swell causing loosening of parts or sluggishness. The piano is then in need of regulation, tightening of parts and lubrication. If the piano is not maintained, parts may have to be replaced or repaired.


The keys are affected in a like manner. Different types of wood are affected differently. For example, softer woods are more able to absorb moisture than harder woods. Keys should be cleaned with a semi-damp cloth with light dish soap, if very dirty. Never use abrasives and keep paint thinner or nail polish away from the keys. If the keys are yellowed sometimes they can be cleaned professionally with some good results; however, sometimes it is necessary to recover the keys. Just give your tuner a call for an estimate for such services.


Dirt can cause felts to be destroyed in time. We recommend a thorough cleaning at least every few years by a technician. We do not recommend that customers clean their own piano. There are intricate parts that can easily be destroyed by a well meaning housewife and result in unnecessary and very costly repair bills.

The Hammers and the Felt

The hammers in the piano play an important part in producing the tone. After a lot of use the hammers become very dirty and worn, as well as developing impressions from the strings they hit. This reduces the quality of the tone. The hammers should be voiced by your piano technician or replaced if necessary. The hammers may also become moth eaten and should be moth proofed once every few years The felts in a piano are affected by moths as well as becoming worn from use and must also be replaced or cleaned after a period of time.

The Case

Even though finishes are made of better materials today, they still should be cared for. Wood can dry out and lose its natural oils. These should be restored with the proper polishes and your piano tuner will be glad to help you. NEVER use aerosol spray polishes or silicone on fine furniture because you can damage your furniture. Always have a competent piano firm refinish your piano because there are parts in the piano that can be ruined by toxic refinishing materials. Call your tuner for his advice.

Your Tuner Technician

Your tuner does not come to take command of your home. He does need your cooperation as piano tuning requires an extreme amount of concentration and the tuner cannot tune if there is any interference. The more cooperation you give him, the sooner the piano will be tuned and the better it will sound. Your tuner’s time is valuable and if it is not possible to keep appointment, please advise him ahead of time in order to prevent him from wasting gas and time. Your piano tuner is a professional craftsman. His fees do not only reflect his needs but the needs of his business as a whole. Piano parts, tools and equipment are very costly as well as vehicles, shop and business office expenses. He is trying to give the best deal he can.

Buying a Piano

When buying a piano one can easily be misled. We highly suggest the services of a qualified tuner technician. There are so many good and bad instruments on the market it is very difficult to know which to purchase Used pianos are another story. In this case, a person can not depend on their own understanding. There are over 4,000 parts in a piano to work properly or malfunction. A reconditioned piano can be reconditioned to any degree. A used piano usually requires work and some dealers want to unload junk. Therefore, the buyer should beware. If you pay a little extra for a technician’s time, you will save a lot of unnecessary aggravation later. Piano teachers are qualified as teachers and not as technicians. If you decide to take a teacher, take a technician as well. Not all pianos that sound nice or play, work properly. The piano may have just had a quick tuning before it was put on sale.