When a piano is ‘in tune’, it sounds uniform across all registers, each note that has 2 or 3 strings (all keys starting with F1) is in tune with itself, giving your piano a pure tone. As the keyboard is divided into 7 full octaves from C to C, each octave has to be tuned such that when played together, the two Cs blend into one note.
Major triads are also used to verify the ‘in-tune-ness’ of your piano – consonant major chords have a harmonious, clear sonority which is noticeably disturbed if the piano is out of tune. A piano tuner has to be knowledgeable about best practices of how to check the good tuning of the piano and what signifiers to employ to achieve and maintain a perfect tune. The contemporary piano is a well-tempered piano – the tuning system that was developed in the late 17th century that perfected the tuning, which, in turn, allowed the use of all 24 keys without the piano sounding terribly out of tune. Some of these techniques date back, and some hi-tech devices are now available to aid the tuner.
Modern standard tuning is known as A440 (A4=440 Hz). All orchestras and music instruments are tuned to it, and there is a device that verifies it). It is advisable but not required to tune to A440, particularly if you are planning on playing with other instruments. If your piano is tuned, say 442 or above your piano will be out of tune with other instruments (unless they are members of Vienna Philharmonic, which famously tunes to 445).
Climate, time, and movement are the strongest factors that affect your piano’s tune. Exposure to dryness and humidity, temperature raises and drops and proximity to heating/cooling devices will make your piano go out of tune faster. Assuming those are under control, the passage of time itself will result in your piano going out of tune.
Moving your piano around (even within one room) will speed up the ‘untuning’, making more frequent maintenance necessary.
Essentially the pins, which anchor the strings, give in to the pressure created by the stretched string and turn, loosening the string and therefore resulting in a lowering of the frequency that the given string’s vibration creates. That is why your piano’s pitch goes down as it gets out of tune, not up – the strings loosen, and the pitch ‘slides’ down, giving your piano a twangy, drunken sound.
Naturally, playing the piano will also make it go out of tune.
Prospero Rodriguez tuning a Fazioli concert grand piano in Naples FL
Here in Southwest Florida we strongly recommend tuning your piano twice a year, due to extreme humidity and heat in conjunction with ubiquitous air conditioning. When the piano is maintained in perfect tune it holds it better, while if you wait for it to start sounding all wrong and out of tune, the single tuning won’t fix it. It will swiftly go out of tune again, and you will end up spending more on more frequent ‘urgent’ tunings.
As with the tuning, consistent regulation maintains your piano in perfect working condition with respect to the action and mechanical parts. Each key has a highly complicated mechanism attached to it. Weather, usage, and age cause tiny screws to come undone, some glued parts to detach, and at times even hammers to break. All of that is addressed during the regulation. Pedal lyre may need adjustment as pedals have to work seamlessly, without sound, and with lyre remaining stable. Excessive use, climate factors, and general amortization may cause the lyre to be loose and sway back and forth when pedals are used – which is not good and may cause permanent damage to your piano.
All in all – the very act of playing the piano will cause it to go out of tune. But that is what the piano is for – so fear not, piano lover!
With world-class piano technicians in the area, your piano will enjoy a long and happy musical life.