It is also a fact that a piano will go out of tune whether it is played or not, due mainly to the constant variations in heat and humidity in the home. Have your piano tuned as often as you feel necessary, but a minimum of twice yearly. Humidity and Your Piano As far as possible, try to maintain even temperature and humidity levels in the room in which the piano is kept. Failure to keep a reasonably uniform environment will necessitate more frequent tunings. Too much humidity can result in such problems as sluggish action and keys, string and tuning-pin corrosion, plus pitch instability.
Excessive dryness can create problems even more serious in nature.
Soundboard splits, loose tuning-pins, warpage, loss of action regulation and pitch drop are all conditions associated with lack of moisture. These problems are, in most cases, completely unnecessary. It is imperative that the piano be kept away from sources of heat such as radiators, hot air registers etc. It is also important that the piano not be located adjacent to frequently opened windows or exterior doors. The sensitive inner mechanism of the piano or action, as it is called, can be thought of as the extension of the pianist's fingers.