Why Pianos goes out of tune
Understanding why a piano goes out of tune, you need to first remember that the whole instrument is always being subjected to different amounts of stress. On an 88 key piano there are approximately two hundred and thirty-five strings. Each string when at international pitch (440 cps) has approximately hundred pounds of tension, so that the iron plate, together with the heavy wooden framing carries a tension of about eighteen to twenty tons.
This tension is not constant because the steel wire used for stringing is of a high form of elasticity. The soundboard only a thin sheet of spruce wood that is about three-eighths of an inch in thickness. If the soundboard is correctly constructed, the whole soundboard becomes a kind of elastic in nature. The more elastic it is, the freer and better the tone the piano can produce. Now for the other part. . .
How sensitive are pianos to season changes?
The short answer is they are very sensitive to changing conditions in the weather. Unfortunately, the way a piano is a construction is extremely sensitive to all changes of temperature and barometric pressure.
Summertime, throughout the coastal areas of there, is moisture in the air most of the time, and rain is frequent. Wood, under these conditions, does swell Nothing will stop that. On the contrary, when the heat is on during the colder months, the air in the rooms becomes much drier and the opposite happens, and wood will shrink. flowering plants or other moisture retainers or humidifiers will help. Keep pianos away from heat ducts and try to keep your home around 42 per cent humidity. This will help to keep your piano in tune longer.