After years of regular use, your piano may have fallen silent when the family member who studied music moved aways from home. Though your home is no longer filled with music, it’s important to remember you piano is still a living, breathing thing. Its wood continues to expand and contract with seasonal changes in temperature and humidity, and the string tension also fluctuates accordingly. If your piano has gone without tuning for an extended period, its pitch may have dropped far below the pitch at which it was designed to perform. It may require a procedure technicians call a “pitch raise.”

When the tension of each string on a piano is raised back up to pitch, the additional load on the pianos structure causes the pitch of previously adjusted strings to change. The only way to achieve a fine, accurate tuning on a piano is to have the tension of all the strings so close to their proper place that altering the tension of one string would affect the others. Therefore, a piano must already be fairly close to standard pitch to be finely tuned.

Pianos that have been subjected to severe changes in humidity routinely need pitch raises before a fine tuning can be achieved. For example, if A-440 has drifted only two cycles per second to A-438, a separate pitch raise is advisable. Most recreational musicians would want to have their pianos tuned before the pitch drops that far. Even if you aren’t bothered by a slightly out-of-tune piano, it’s best to tune the piano on a regular basis to avoid tuning instability and the extra cost of a pitch raising procedure.

Like your car, your piano is a major investment which deserves to be protected by regular servicing, which can head off preventable problems in the future. But most importantly, your piano will sound its best and give you and your family the most pleasure when it is tuned regularly and kept in proper playing condition.

Swelling and shrinking of the piano’s soundboard is the most immediate and noticeable effect of humidity change. The soundboard, a sheet of wood approximately 3/8 of an inch thick, is made with a slightly crowned shape. The strings pass over the soundboard and are connected to it by a wooden piece called a bridge. The upward crown of the soundboard presses the bridge tightly against the strings.

As the moisture level in the soundboard increases during periods of high relative humidity, the crown expands and pushes the bridge harder against the strings. The strings are stretched tighter and the piano’s pitch rises. Because this increase in crown is greater in the center of the soundboard than at the edges, the pitch rises more in the middle octaves than in the bass or treble registers.

During periods of low relative humidity the soundboard shrinks, reducing the crown and decreasing pressure against the strings. The pitch drops, again with the greatest effect noticeable in the center of the keyboard. When relative humidity returns to its previous level, the average pitch of all the strings will return to normal, although the exact pitch of individual strings will be slightly changed from their original settings. Thus, a piano will only stay in tune as long as the relative humidity level in the air surrounding the soundboard remains constant. Extreme humidity changes require making greater changes in string tension to bring the piano into tune. This upsets the equilibrium between the string tension and the piano frame, and the piano never becomes stable.

Keeping the humidity level around your piano as constant as possible will help it tune longer as well as slow such damage as soundboard cracks, loose tuning pins, and glue joint failures. The first and simplest precaution you can take is to position your piano away from areas where it would be exposed to extremes of temperature and humidity such as heating and cooling vents, stoves, doors and windows. Direct sunlight is especially damaging. If your home is not well insulated, an interior wall is preferable to an outside wall.

Controlling the humidity within the home is another step you can take to preserve your instrument. In most areas of the country the relative humidity is very low during the cold winter season, and very high during the spring and summer. In other areas these humidity cycles are reversed. Wherever you live, you have probably noticed the symptoms of low RH (shocks from static electricity when sliding out of a car or after walking across carpet), and the signs of high RH (limp, soggy-feeling newspapers and sticking doors). To monitor RH changes in your home, you may wish to purchase a moderately priced wall hygrometer available from most instrument supply companies or electronic stores. 

Use of a room humidifier during dry seasons will help somewhat. However, too much moisture added to a room during winter months can cause condensation to form on cold surfaces such as windows, eventually causing mildew, rot, and in extreme cases, damage to the building structure. During the humid season de-humidification is needed. If your humid season is winter, keeping the home evenly heated will help. However, humid summer situations will require much more elaborate de-humidification systems. Unfortunately, it is seldom possible to adequately control the relative humidity of a piano by controlling the room environment alone.

A very practical and effective answer to humidity problems is to have a humidity control system installed in the piano itself. These systems consist of three parts: a humidifier for adding moisture to the air, a de-humidifier for eliminating excess moisture, and a humidistat or control unit which senses the RH of the air within the piano and activates the system to ad or remove moisture as needed. These systems are designed to maintain the RH of the air within the piano at the ideal level of 42%. The components are installed out of sight, inside the case of a vertical piano or under the soundboard of a grand. They are easy to maintain, and can be installed by your piano technician.

Regulation is the adjustment of the mechanical aspects of the piano to compensate for the effect of wear, the compacting and settling of cloth, felt and buckskin, as well as dimensional changes in wood and wool parts due to changes in humidity.

The three systems involved in regulation are the action, trapwork and damper system. The action is the mechanical part of the piano that transfers the motion of the fingers on the keys to the hammers that strike the strings. It is comprised of over 9,000 parts which require adjustments to critical tolerances to be able to respond to a pianist’s every command. The trapwork is the assemblage of level, dowels and springs that connects the pedals to the action affecting sustain and dynamics. The damper system is the mechanical part of the piano that stops the vibration of the string when you release the key and is controlled by the ket and pedal system.

All upright and grand pianos need periodic regulation to perform their best. Frequency of regulation is dependent upon amount of use, exposure to climatic changes, and the instrument’s quality, age and condition. New pianos may require regulation in their first year because setting and compacting of parts sometimes necessitates adjustment.

If your instrument displays a lack of sensitivity or a decreased dynamic range, it’s a candidate for regulation. If you notice that the keys are not level, meaning that some are higher and lower than the rest, the touch is uneven or that the keys are sticking, the need for regulation is indicated. However, a sluggish action or deep grooves in the hammers indicate the need for reconditioning or repair. Ask your technician to show you what needs adjustment on your piano.

No amount of practice can compensate for a poorly maintained action. Poor legato touch, chord playing where all notes of the chord don’t speak clearly, a gradual loss of subtlety in phrasing and an inability to execute quick passages or note repetitions evenly may be the fault of the piano – not the player.