Tuning a piano
When tuning a piano for the first time, I use computer software to record a few notes separately. This creates a unique tuning profile and the software calculates a custom stretch. In other words: it calculates how to achieve the best tuning curve for this particular piano only and how to minimize the entropy (disorder, degeneration) between all pitches.
The hardest part of tuning a piano is not necessarily making a note sound great, but to make sure that all pitches are in the best possible ratio to each other. We call this equal temperament or equilibrium temperament. The computers accuracy of calculating this best possible ratio cannot be achieved with human hearing.
The starting point for every single tuning is to make sure that the ‘A’ of the fourth octave (this is the A right from middle C) is set to 440 Hz. This is defined being the concert pitch. When a piano is tuned to this pitch, it is possible to play with other instruments.
Some pianists prefer to have the concert pitch set to 442 Hz. It supposedly makes the sound of a piano more bright and brilliant. I tuned several piano’s to 442 Hz pitch, but honestly I can’t say I noticed a big difference compared to 440 Hz . Nevertheless, it is by no means a problem to tune the piano to 442 Hz. However, ideally you should not change the piano’s concert pitch too often: it is not conducive for tuning stability.
I use a Jahn tuning hammer because this hammer allows me to tune in the best accurate way. A key is tuned by turning the tuning pin. If the tuning hammer even slightly bends, not all the energy will transfer directly to the tuning pin. The Jahn tuning hammer is made of carbon fibre, also known as graphite fibre. This material is stronger and stiffer than steel, but also much lighter. It allows the piano tuner to transfer the energy of their tuning hammer directly to the tuning pin, making it possible to tune the key more accurately. With my Jahn tuning hammer I am certain that there will be no energy loss because carbon fibre can’t be bend. So it is straight, or it is broken. I love this tuning hammer and I would not like tuning a piano without having this specific tool.
Tuning a piano requires attention, concentration and time. Don’t rush but prefer a calm, controlled approach and work accurately. Invest in good tools and learn how to use them. This blog is intented to assist you in tuning a piano, but you are solely responsible for the instrument you are working on.
The lowest bass notes are made of a single copper wounded string. Use your fingers to guide from the string to the tuning pin. In this way you make sure you are turning the corresponding pin of the string you want to tune.
When turning your tuning hammer, make sure you turn it to the point where you are slightly above the desired pitch. Then push it back a little till the pitch is correct.
If you’d bring the pitch immediately to the right pitch, by the time you are done you’ll end up with a pitch being flat. This is caused by a phenomenon called the moment of inertia: the part of the tuning pin which is firmly tightened in the wooden tuning block resists the rotation of the tuning hammer. The further away the lower part of the tuning pin is from the axis of rotation (the place where the tuning hammer is placed on the tuning pin), the greater the contribution of that part to the moment of inertia. Due to this moment of inertia, the part of the tuning pin in the tuning block will not yet have taken up the same position as the part where your tuning hammer turns this pin. Only by tuning the string a little sharp, you make sure that the full lenght of the tuning pin made the minimum rotation necessary to reach the desired pitch.
When a piano has not been tuned for a long time, first turn the tuning hammer counterclockwise. This will decrease the string tension. If there is a friction point between the string and the piano’s frame (caused bij oxidation for example), the friction point will be loosened, making the chance of breaking a string smaller. If you’d pull up the string straight away, a string could break because of an excisting friction points.
If you are an unexperienced piano tuner, from a safety point of view it’s always advisable to start turning counterclockwise. You wouldn’t be the first person that unintentionally turns a pin which does not correspond with the string you want to tune (ask me how I know that). If you turn the pin counterclockwise and the pitch doesn’t drop, you are working on the wrong pin. But if you are turning it clockwise and the pitch doesn’t go up, chances are likely you will not realise you are working on the wrong pin till suddenly a string snaps.
After the lowest bass notes there comes a section with two copper wounded strings per note, and after that every note has even three strings. You’ll need mutes to mute a string so you can only hear one string vibrating. So if you want to tune a note that has two strings, you add a mute between the string of the note you want to tune and a string of the nearby note. In this way you hear one string of the note you want to tune. Once you have brought this one up to the desired pitch, you remove the mute and start tuning the other string. The string you allready tuned serves as a reference for the one you are going to tune next. As you increase the tension of this string, you want to achieve the sound becoming a so called unison: a pure tone without any beats. Once you have established that, the strings are back in phase.
To tune a note that has three strings, you need two mutes. After muting the outside strings you can start bringing the middle string to pitch. After that you remove one mute to tune the second string and then remove the last mute for the final string.
When turning the tuning hammer, apply as little torque as possible: no major clockwise or counterclockwise swerve. The more subtle, the better. The more frequently a piano is tuned, the less rotation of the tuning hammer is required. This is key for getting a more stable and holding tuning.
Never bend the tuning hammer! By bending I mean pulling the tuning hammer towards you or away from you. This causes the tuning pins to bend and getting loose in the pin block.
Once you have tuned all keys, play the piano and listen for any beats. Make sure you hear clear unisons. If you hear any unwanted beats, find the string that is out of phase and bring it back to correct pitch. Do all keys sound pleasant and without any beats? Congratulations, you have tuned a piano!
Very far out of tune pianos
Sometimes it isn’t possible to tune the piano directly to 440 Hz. This is often caused by a piano not having been tuned for a very long time (several years in a row). It can also be caused by the age of the instrument. This causes the pitch to drop, sometimes well below standard pitch at which it was designed to perform.
If this is the case with your piano, the risk of breaking a string is very high if one raises the piano immediately to concert pitch. Also the tuning will not hold long, due to the large difference in tension on the strings before and after tuning. In order to bring the piano back to its standard pitch again, it may require a procedure called pitch raise, after which it can be tuned again.
But sometimes the piano can no longer get his standard pitch back or even tuned properly due to mechanism failure, a damaged soundboard or other problems the piano is suffering from. Should this be the case, I will report it to you immediately.