Frequently Asked Questions

The short answer: Changes in climate – in particular, humidity – cause your piano to go out of tune. Read on for a more detailed explanation of why this is. 

A piano is largely constructed of wood and metal, each of which physically react to the weather. The wooden soundboard is attached to the bridges, which in turn contact the strings and partly define their speaking length – that is, the length of wire which is free to vibrate and produce sound. 

The length of the string, as determined by its tension, equates to that string’s pitch. The higher the tension, the shorter the string becomes in its speaking length, and the higher the pitch. As summer approaches, the relative humidity rises, and the wooden soundboard absorbs that moisture. In turn, the board expands. Because the board is fixed to the rim of the piano, the only movement possible is up or down. A healthy soundboard is also “crowned,” or higher in its center than at its perimeter. Thus, humidity causes the board to rise, and with it, the bridge. As the bridge rises, it lifts the strings with it, but the opposite end of the strings – anchored by the pin block – remain at their original height. This results in an increased tension, shortened speaking length, and raised pitch of the strings. Because the soundboard is free to rise further at its center than it can near its fixed edges, the strings along the bridge rise to different extents. Thus, the result of a humidity rise is a piano which has not only raised its pitch, but has done so inconsistently, such that the various registers of the instrument have become out of tune relative to one another. This process runs in reverse as the humidity drops in the winter, and the piano will be flat. 

When temperature changes, the cast-iron plate which anchors the tail-end of the string expands (heating up) or contracts (cooling down). This of course causes the strings to increase or decrease in tension, though in a more consistent way relative to each another. 

Yes. You can find ways of controlling your room’s climate, or the climate of the piano itself. 

The former may involve keeping the room at a consistent temperature and incorporating a climate control system into your HVAC. Such systems can be prohibitively expensive. If that is unaffordable, you can have a Piano Lifesaver system installed onto your instrument. This system uses a sensor, heat bar, and moisture source to keep your soundboard at a more stable moisture content. 

Contact us to have a Piano Lifesaver installed if this sounds good to you!

The standard recommendation is that you should have your instrument tuned twice per year – corresponding to the major seasonal shifts. When your radiator or heating units kick on in the winter, your home will dry out and cause your piano to drop in pitch. When your AC kicks on in the summer, this means the relative humidity is likely increasing, which causes your piano to go sharp. (See the answer to “Why does my piano go out of tune” for the details). 

If you consistently have your piano tuned during these shifts, the degree to which the strings need re-tensioning will be less than if you let it go through the seasons untouched. When a piano’s tension is sufficiently far from its optimal point, at least two passes in tuning must be performed – a rough pass to get the tension equal and stable across the soundboard, and a second pass to bring the strings to their proper frequencies. See “Our Offerings” for a description of a pitch correction.