Ideally a piano should be tuned every six months although with modern pianos which get moderate use a yearly tuning is acceptable. A brand new piano usually takes a few years (7-10) to "bed in" (or for its inner tensions to reach an equilibrium) and therefore would require tuning more often; about once every seven months with moderate use.
With older pianos it varies according to their age and condition. Some sturdy well made older pianos only need tuning once a year whilst others need tuning every 6 months. A wood framed piano should ideally be tuned every 3 months.
A piano which gets medium to frequent use would need tuning at least every half year.
A professional pianist (and the enthusiastic amateur) who use their piano for most of their practice would have their piano tuned every 2-3 months, as well as having it periodically voiced and regulated.
A concert piano should be regularly voiced and regulated, and tuned before each performance.
A piano that is new to the home would require a short period of time to acclimatize to the new temperature and humidity of its surroundings, usually 2-3 months so it's better to have it tuned after then but of course if you're eager to start playing then by all means get it tuned straight away and then again when it has settled.
In conclusion, it's better for the piano to be tuned regularly; keeping your piano in tune at A440Hz means keeping an even tension across the strings which will maximize its condition, quality and even lifespan. Older and neglected pianos are sometimes an exception to this, they are often better tuned lower, usually A435Hz. Most pianos get tuned on a yearly basis but it all depends on the age and condition of the piano, the amount of use it gets and its importance to the owner. Shaun reminds his customers by telephone (with their consent) yearly or half yearly if requested. He can advise you on this.
Seasonal humidity changes are the main reason a piano goes out of tune and why a piano goes out of tune even when it has not been played. Even though the pianos soundboard has been sealed water vapour can still get in and out through the end grain. This causes the soundboard to expand or contract depending on the increase or decrease of humidity levels. When the soundboard swells it pushes the bridge out causing the strings to tighten raising the pitch, when it contracts the pitch drops.
The high tensile steel strings of an upright piano exert about 18 metric tons of pressure on the pianos load bearing components and are very slowly pulling themselves out of tune. Other factors such as intensity of use also have an influence.
Seasonal changes mean the pitch rises and falls but string tension and intensity of use cause it to drop meaning over time the pitch will usually go down.
The pianos load bearing components-the frame, the pinblock, the tuning pins, the soundboard, the ribs and the bridges all work together to withstand the string tension, and the strings themselves are "scaled" i.e. designed according to their pitch, length and diameter to exert an even tension across the range of the piano when they are in tune with note A49 tuned at 440 cycles per second (or Hertz). These load bearing components are also constructed to move the least when the strings are at this tension.
This interdependent and intricate relationship means that the load bearing components are holding the strings in tune for the maximum time possible whilst the strings are in turn holding these components steady ! This is one of many technical aspects a piano company's design department must consider before looking at the aesthetics of a new design.
The upshot of all these facts is that if a piano is below pitch these components will not maintain the same rigidity, wooden parts are more likely to separate, or even warp and metal parts will creep, all adversely affecting the pianos structure and its tuning stability.
To avoid getting too hysterical, it should be mentioned that these things only happen with long term neglect, in the short term the piano will go out of tune faster than necessary when below pitch and if it is tuned a minor third below pitch (3 semitones) the piano will not stay in tune at all.
If a piano is above pitch or at an uneven tension these load bearing components are in danger of being seriously damaged by string pressure necessitating expensive repairs.
Fair enough, you're the boss. But if you were to get it tuned you should notice the difference; each note would sound crisper and more well defined, and if the pitch needed raising the whole piano would sound much brighter following
You also might like to consider reading the section above entitled, "why does a piano need tuning?"
You can't compare the turning of a pianos tuning pin to the tuning of a guitar. This is a gross oversimplification and doesn't take into account the tensions along the string, within the tuning pin and the piano itself. The fact that the piano must sound harmonious in every key is another difficulty the amateur will encounter.
The tuning pin.
Lift the top lid of an upright piano or remove the music desk of a grand and you will see around 200 tuning pins protruding from the frame. You are only seeing around 1/2 of each pin as the rest of them are held tightly in holes in a laminated block of wood (usually maple), under the frame. This is called the pinblock. A modern tuning pin will be between 2 and 2.5 inches long. These mild steel pins are held so tightly in the pinblock that when the tuner turns them with his/her crank the rear part of the pin will turn a short while after the front part due to the pin's elasticity.
Turn this pin until you think the string is in tune and then move on to the next as you would in a guitar and there will be a further change in pitch as the forces within the pin reach an equilibrium rendering your efforts futile. The professional piano tuner uses a certain technique to get round this problem. It's not enough to just know this method, it must be practiced over and over again to fall within the tuners grasp; how much time do you have?
The note that you hear when the string vibrates is not the full length of the string, it is a portion known as the speaking length. There are several other parts crossing various friction points which are all at different tensions. The speaking length has the lowest tension whilst the coil around the tuning pin has the highest.
Tighten or loosen the string until it sounds in tune and move on to the next and the pitch of this note will continue to alter until the different tensions along its full length reach a balance. Once again the method used to counter this problem must be practiced repeatedly to gain control over these forces. Still want to tune your piano? Read on.
If a piano is only 5 beats below pitch at A435Hz and you start to tune it up to the required pitch the resultant increase in pressure will push the strings into the bridge which will in turn press into the soundboard flattening its crowned shape a little. The more strings you tune the further the bridge will push in, causing the strings to slacken a little resulting in a secondary drop in pitch. The tuner must take the strings over the required tension in order for them to drop to the correct pitch. This is called an allowance. The piano is then fine tuned.
The flatter the piano is originally, the higher the allowance must be. Go too high and the strings will snap as they reach their breaking strain, too low and you'll have to tune the piano a third or even a fourth time. That's around 200 strings, times 4; very laborious.
Harmony in every key.
Musical instinct and a good sense of pitch are not enough to tune a piano. Music occurs naturally enough; you can hear it in birdsong and the rhythms of nature, but mankind has quantified and rationalized it. The scales that we have in western music are not perfect, not if you want to include every scale in an instrument. Each interval must be tempered and all must be slightly out of tune to accommodate each other; out of tune maybe, but not so much so as to offend the ear.
This is called Equal Temperament, all modern music is based on this, and it takes hours of continued practice to achieve this at a competent level.
So yes, you can tune your own piano. All you have to do is invest at least 3 years of your life and enroll on one of the few college courses left in this country or find an experienced piano tuner who is willing to take on an apprentice. You then knuckle down to some intensely focused study and practice.
Or you could let Shaun do it!
Make sure your piano is tuned regularly. It will give the optimum tone and maintain its condition and quality when kept at A440Hz.
Don't put it in front of or too close to a radiator or other heating device. It will be ruined in no time. It is best placed against an inside wall and not in a direct draught although good air circulation is beneficial.
If the room is being plastered move the piano as far away from that room as possible. The increase in humidity as the plaster dries has caused pianos to be written off.
Don't put plants or drinks on top of your piano. Spillages can cause serious damage to the action, casework and load bearing components, it's best not to tempt fate. Dried flowers are fine.
Some aerosol polishes can damage a pianos casework and keys. A lightly dampened cloth will remove most stubborn marks. Burnishing cream is one of the best polishes for open pored surfaces, to be sure try it first on an area that's not highly visible. Avoid getting any moisture on the main wooden body of the keys. Shaun can supply burnishing cream, a polishing kit for high gloss polyester/polyurethane surfaces & one for nylon topped keys.
The room is best kept between 65-70 degrees Fahrenheit (18-22 degrees Celsius) and at a humidity level between 45% and 60%, you can buy a max-min thermo/hygrometer from some gardening centres with a greenhouse section
If you're emigrating with your piano, make sure it's kept in a sealed unit when transporting it across water. Humidity levels are far higher at sea.