What Causes a Piano to Go Out of Tune?
Having your piano tuned regularly is akin to getting a regular physical yourself. It confirms you are in good health or identifies an issue early so that it may be corrected immediately and successfully. When your piano sounds in tune, the uniformity of the corresponding pitch classes (C to C octave) blends perfectly. The slightest disruption of this blending becomes noticeable as the piano goes out of tune, making your piano sound ‘off’ and flat. What causes the piano to go out of tune is the loosening of the tuning pins that hold piano strings stretched out. As the tuning pins turn, the string’s tension diminishes, causing the pitch to lower.
The further complication is that half of the keyboard has more than one string per hammer (mid register has two and upper has three), and those are looped. So if one of the three strings of any given pitch loses tension, that pitch acquires a twang or split tone. Some manufacturers (like Blüthner, for example) don’t loop but individually wrap every string, which contributes to keeping the piano tuned for longer. However, no design ‘trick’ could eliminate the necessity of piano tuning.
Playing the piano ‘knocks’ it out of tune, as well as the climate and the environment in which the piano resides. As the piano is exposed to humidity, all wooden parts (of which there are thousands, including the piano body itself) swell up and expand, causing some action malfunctions (sticky keys, loose hammers). The rusting of the strings can also occur, which is particularly dangerous near the tuning pins. Conversely, the extra dry environment makes the wooden parts contract and shrink, often causing cracks in the soundboard (which is responsible for the resonance and the totality of the ‘voice’ of the piano).
The humidity/dryness fluctuation is particularly dangerous as the soundboard expands and contracts in response to those factors. The action can get loose and sloppy, too. All those environmental conditions affect the pin block where tuning pins are embedded (as it is made of wood), and as they turn (even an iota), the pitch begins to travel. That is why expensive premium pianos are always advised to be equipped with a humidifier/dehumidifier system that can mitigate humidity levels and protect the integral parts of the piano from being damaged.
The acrylic pianos are much more immune to those conditions due to the nature of the acrylic alloy, and you can read more about them here. The grand piano has the frame and the strings positioned horizontally, while upright pianos are vertical. That affects how piano strings stretch over time, and at times an upright requires a more frequent tune-up.
How do you know if your piano needs to be tuned?
When your piano starts sounding flat, twangy, or ‘drunk’ – it’s time for tuning. If you notice the visible onset of rust on the strings, the issue needs to be addressed right away. It is particularly pertinent to those living in the southern climate with high humidity and near water. If you notice that some keys remain depressed even a little bit, it indicates that the action needs regulation.
An acoustic piano is a complicated instrument with a highly sophisticated mechanism responsible for proper key operation. Eighty-eight keys of the entire keyboard mean 88 double-escapement action units have to function in perfect harmony with one another. Weather conditions and piano exposure to the elements affect all 88 units randomly, that is how you end up with one or two single keys being stuck, or individual hammer coming undone, etc. There is glue and felt involved in the key’s mechanism, which is also subject to temperature fluctuations.
How often should you get your piano tuned?
How frequently you tune your piano depends on multiple factors. If you are a piano teacher, professional pianist, or piano student, using your piano will be consistent – you should have your piano tuned several times a year. Many pianists opt for frequent tuning and regulation as it keeps everything working perfectly and prevents significant issues from developing. The recently purchased piano should sit in the new environment to ‘acclimate’ to it before the regular tuning schedule is established. If the piano is at a concert hall, it must be tuned before each performance and maintained and regulated in between. For an average household, regular tuning every six months should suffice.
You should listen to the sound of your piano regularly and play (if you don’t play yourself, ask someone from family/friends who does) some major chords and scales across the keyboard. That will reveal the out-of-tune piano right away. If the piano remains out of tune for a while, it ‘gets used’ to it. The pin block and steel strings have tension memory and will return to the out-of-tune position after the tune-up. That is why it is best to maintain your piano in tune over time so that string tension always remains the same. The good rule is to tune the piano right after the seasons change, like in the fall and the spring.
Side note: if you are living in perpetual summer, schedule your piano maintenance after a significant humidity change occurs. Home pianos are more subject to climate effects than those at a concert hall.
What happens in tuning?
When a reputable piano technician performs a professional tuning, your piano pitch will be tuned to an international standard of A440 (‘a’ above middle ‘c,’ aka A4 = 440 Hz). This particular ‘A’ is what all instruments tune to, so to match the pitch across the entire orchestra, the standard of A4 is established and followed. Otherwise, any ensemble (any number of instruments) with the piano will sound appalling and out of tune. A qualified piano tuner will have an electronic device that will confirm the exact frequency of every note rather than relying on a perfect pitch.
When the entire set of piano strings is appropriately cared for, your piano will have a beautifully mellow and uniform sound. You will hear your piano technician play major chords and scales, which help verify the tuning of each octave across the keyboard. Piano technicians usually take out the keyboard to check for any visible action issues and ensure the felt is in good condition when a hammer strikes the string. The excessive grooves or hardening of the felt will affect the sound quality.
How much does it cost to tune a piano?
The cost of piano tuning depends on the reputation of your piano tuner, location, competition, supply and demand, and the kind of service your piano requires. The national average is about $120 for a regular maintenance tuning. Still, if you have to make action regulations and voicing (hammer needling or shaving), this easily elevates the price by hundreds of dollars. In major markets like New York, Los Angeles, Boston, Chicago, San Francisco, etc., the average is about $200 – $250 for a professional tuning by a qualified piano tuner. Legendary and in-demand piano technicians can command a much higher price and are usually booked out months in advance. Some hard-to-reach, smaller upscale communities such as the Bahamas see the average piano tuning run $500 as supply and demand determine the pricing. An excellent verbal reference from a professional musician in the area is advisable when selecting your piano technician.
Is it worth tuning an old piano?
Whether to tune an old piano depends on the condition of the piano, its sentimental value, and its potential worth. If the piano value is under $1000 and needs $1000 worth of tunings, it depends on what that particular piano means to you. If it is a vintage Steinway, Bluthner, or Bosendorfer in need of serious work – it will be well worth the money to invest in bringing such an instrument into good shape, for it will have decades of good use. The critical factor is having a fair assessment of the piano’s value by a highly reputable piano technician. Most piano manufacturers make pianos that can last 30-40 years in excellent condition but wear the tear, climate damage, and amortization play a significant role in how any given piano ages. So the short answer – is yes. But make sure to seek a trustworthy professional evaluation before putting too much money into an old piano.