Why Does A Piano Need Tuning?
"If I move my piano into another room, does it then need to be re-tuned? My grandfather had a nice old upright that he never had tuned. Why does my piano need regular tuning? We always kept a jar of water in the bottom of the piano. Does this help keep the piano in tune? How often should I have my piano tuned?" Piano technicians hear these questions all of the time. Tuning is the most frequent and important type of piano maintenance, but can be the least understood. We'll take a look at why pianos go out of tune and how you can help yours stay in better tune between tunings.
New pianos are a special case; their pitch drops quickly for the first few years after manufacture as new strings stretch and wood parts settle. It's quite important that a new piano be maintained at proper pitch (A-440) during this period, so the string tension and piano structure can reach a stable equilibrium. Most manufacturers recommend three to four tunings the first year, and at least two annually after that.
After initial settling, seasonal change is the primary reason pianos go out of tune. To understand why this happens, you must realize that a piano's main acoustical structure, the soundboard, is made of wood (typically 3/8-inch thick Sitka spruce). And while it is true that wooden soundboards produce a wonderful sound, they also react constantly to changes in the weather. When humidity goes up, a soundboard swells, increasing its crowned shape and stretching the piano's strings to a higher pitch. During dry periods, the soundboard flattens out, lowering tension on the strings and causing the pitch to drop.
Unfortunately, the strings don't change pitch equally. Strings near the soundboard's edge move the least, and the one's near the center move the most. So, unless it's in a hermetically sealed chamber, every piano is constantly changing and going out of tune!
The good news is there are some simple things you can do to keep your piano sounding sweet and harmonious between regular tuning appointments. While it's impossible to prevent every minor variation in indoor temperature and humidity, you can do things to improve conditions for your piano.
For starters, locate the piano away from direct sunlight, drafts, and heat sources. Excess heating causes extreme dryness, so try to keep the temperature moderate (below 70 degrees) during the heating season of winter.
A portable room humidifier, or a central humidification system will combat winter dryness in very cold dry climates.
Portable dehumidifiers or a dehumidifier added to your air-conditioning system can remove excess moisture during hot, humid summers.
If controlling your home's environment is not possible, or if you just want the best protection possible, you should have a humidity control system installed inside your piano. These are very effective in controlling the climate inside the instrument itself. Along with improving tuning stability, these systems help minimize the constant swelling and shrinking of your piano's wooden parts. The most important part of such a system is the humidistat, this device monitors the relative humidity within the piano and adds or removes moisture as needed. Jars of water, light bulbs, or other such "home remedies" have no control and can actually do more harm than good.