Why does a piano require regular tuning?
A piano is built largely out of wood. Slight changes in temperature and humidity can affect a wooden structure considerably because wood absorbs moisture and swells. When this occurs, the relationship of steel wire strings to the bridges and sounding board of your instrument is changed. As a result, the piano goes slightly out of tune. This is entirely normal – it is not a fault in your instrument. Excessive exposure of your piano to rapid changes in temperature and humidity can have serious affect and damage the piano.
Why does a piano go out of tune?
The piano strings are under a great deal of tension that is supported by the piano rim, plate, pinblock, tuning pins, bridges, and soundboard. Anything that affects the position of any of these parts will cause a change in tension and make the piano go out of tune.
Humidity Changes - Although a soundboard has a coating of carnish or lacquer, moisture from the air can seep into and out of the wood, mainly through the end grain, causing the crown to increase and diminish. This is the most important fator that causes a good piano with tight tuning pins to go our of tune. A piano goes flat, particularly in the midrange, in the early winter when the dry heat of the furnance draws moisture out of the soundboard. It goes sharp again in the spring when you turn the air conditioning on for the season.
Temperature Changes - Fluctuations in room temperature surronding a piano cause less of a change in tuning than humidity changes do. However, direct sunlight or heat from stage lights is so intense that it can cause rapid changes in the tuning.
Stretching of the Strings - Piano wire has a lot of elasticity, and is begins to stretch as soon as you pull it up to pitch. New strings strethch the most during their first few years in a piano. Because of this stretching, many new pianos sink a quarter step flat within a few months after delivery, thus the importance of the complimentary piano tuning 90 days after the piano is delivered to the new home or venue. Some piano tuners and rebuilders stretch their new strings with a small roller immediatly after pulling a piano up to pitch. This procedure helps, but if overdone it is harmful to the strings. The louder and more frequently you play a newly-strung piano, the faster the strings will stretch, and the sooner the piano strings will stabilize.
Slipping Tuning Pins - This factor doesn't enter into the tuning of a good quality new piano, in which the pins should be so tight that the string tension doesn't cause them to turn. In an older piano that has been exposed to regular seasonal humidity changes for many years, however, the pin block loses its tight grip on the pins. When the pins get loose, string tension causes them to rotate slowly, over a period of months, allowing the pitch to go flat.
Playing the Piano - The louder and more often you play the piano, the faster it goes out of tune by a small amount. This is due to equalization of tension along the length of the strings. The better the piano tuner "sets the strings" during tuning, the less this happens.
How often should a piano be tuned?
We usually recommend our customers at least 2 or 3 piano tunings per year for a piano getting average use in the home. Ideally 4 piano tunings spaced through the year to cover the seasonal changes would be best. A new piano settling into a new environment may need more regular tuning for the first year or two. These suggestions only apply to pianos in the average home. Pianos in music schools and teacher’s pianos should be tuned more frequently as they receive heavy use. Studio and concert pianos are tuned before every concert or recording.
What is a Pitch Raise?
If the pitch of your piano has slipped below that of concert pitch (A440) you may wish to consider having the pitch raised. This may happen if you have not had your instrument tuned regularly or in conditions of extreme temperature or humidity. It is particularly recommended to keep your piano at concert pitch if you are using it for chamber music (ie. with any other instruments or singers). A pitch raise can be carried out by a piano tuner, and constitutes a very rough overall piano tuning to pull the piano up to pitch. It would then be necessary to have another fine-tuning at the new pitch to obtain an even and stable tuning. If the pitch has to be changed considerably it may be necessary to have another tuning fairly shortly afterwards.