Q - Does a piano have to be tuned to concert pitch (A-440 cycles-per-second standard)?
A - The piano can be tuned do a different standard although concert pitch is highly recommended. In some cases, an older piano may have some rust on the strings or loose tuning pins. When repair is not considered a reasonable option, you may be advised to have the instrument tuned at a lower frequency (e.g. a frequency at or close to the current pitch) rather than risk breaking strings or having an unstable tuning. When tuned to another base frequency, the piano will still have all the notes in proper scale relative to the other notes and sound pleasant to play. However, if someone wants to play along on another instrument, the piano will be out of tune with the other instrument which would need to be tuned to match the piano that is not tuned to concert pitch.
Q - What can make it difficult for the piano tuner to tune the instrument?
A - Tuning requires a lot of listening to small variances in the sound of the strings. Below is a list of a few things that can make it difficult to hear the piano during tuning:
Running water makes a type of "white noise" that masks the ability to clearly distinguish one frequency from another. Therefore, washing dishes while I'm tuning can be a problem.
Vacuum cleaner noise is similar to running water.
The high voices of excited young children (Yes I love kids ... but a high screech just when you are bringing a string into pitch can set me back a bit while my ears readjust.)
Lots of noisy vehicles going by (not much you can do about this).
Rattling noise of someone reading a newspaper.
Video games (although most of the time a normal TV program at reasonable volume is not a problem)
A small dog barking with a high-pitched bark. (I love dogs too, and most customers have dogs that like me or at least adjust to my presence.)
Q - What can cause a piano to be a difficult one to tune?
A - If the piano is older or has been in a harsh environment, the tuning pins can become loose. If the tuning pins don't stay where you put them, the strings obviously cannot stay on pitch. Sometimes a piano with loose pins can be tuned at a lower overall pitch although it could not be pulled up to concert pitch due to loose pins inability to handle higher tension. If a piano has rusty strings and in the first several octaves several strings have broken, it has become apparent that the piano may not be tunable or it should be tuned at a lower frequency.
Q - Why do some notes sound softer/louder or more mellow/harsh than others?
A - This is generally caused by one or more things:
In a piano that has had a lot of use or is older, the hammer felt is not uniform along the scale. Harder felt will sound loud or harsh while softer felt can be mellow or even too mellow to appreciate. The piano may need "voicing" which is working on the felt to harden some with a special solution and soften others with a special needling tool.
The hammers may need to be replaced. After replacing hammers, they still need to be filed and voiced to get a uniform sound across the scale.
The piano may need "regulation". There are a number of fine adjustments for each key. These adjustments, called regulation, together impact how the mechanism on each key works to cause the hammer to strike the strings. If out of adjustment, this can contribute to a non-uniform sound across the keyboard.
There may be broken parts in the mechanism (the "action") that, although they allow the hammer to strike the strings, limits the range of motion or limit the ability of a hammer to correctly strike the strings.
The strings may be worn. This may be more apparent in the bass section where the strings have the additional copper windings. The windings may come loose, corroded or dirty causing each one to sound different. Depending on the issue there may be some stop-gap fixes the technician can implement for certain string problems. Other times, only a new set of strings will completely solve this issue.
Q - How is a piano tuned?
A - The piano is tuned by first setting the pitch. For concert pitch, the standard in the United States is A = 440 cycles per second. Tuners generally set A or C from a tuning fork or some other accurate pitch source. Once the pitch has been set on the one note/key, the tuner can set each note in the rest of an octave to the correct frequency by listening to the relative differences between the notes of the scale. The tuner has learned to listen to certain intervals to accurately set the pitch of the other notes in an octave. Common intervals used in tuning include fourths, fifths, major and minor thirds, 6th, octaves, and even tenths and seventeenths. The tuner accomplishes this task by not only listening to the root notes but also to the harmonics, or "partials", of the intervals.
Q - Is a piano tuned by ear or electronically?
A - Most tuners learned to tune the piano "by ear" (aurally) after first setting a single starting pitch, usually A or C, from a source such as a tuning fork. Every piano, even those of the same model and design, have a few differences called "inharmonicities" due to variations in the components. These are accounted for by the tuner who carefully listens to tuning intervals and setting each note accordingly. Over time, the technology and software has been developed to do much of this providing a visual reference designed into an electronic tuning device. Aural vs. electronic tuning remains a point of discussion regarding whether the piano can be tuned as well electronically compared to aurally. In my experience I have found it beneficial to use both at times noting, of course, that the ear is the final judge if the electronic device offers disagreement.
Also note that the unisons (most of the piano has 3 strings per note) are tuned by ear regardless of whether an electronic aid is utilized. For example, two of the three strings are muted with either rubber or felt mutes. One string is set to the correct pitch either by ear, aurally, or using an electronic tuner. Then the other two notes are each tuned, one at a time, to match the tuned string. This step of matching the other two strings is done by ear regardless of how the pitch of the first string is determined.
Q - What happens when there is a broken string?
A - Sometimes a string was broken before I arrive. Other times the tuning process, that adds tension to the strings, will cause a string to break. There are two solutions, one is to replace the string. The other is to splice the string. There is a process by which a tuner can splice a short piece of new string onto the broken string. If done correctly, the string will be stable, stay in tune, and not easily break again. When one of the thick double-wound bass strings break, this is generally the best solution. For the treble strings they are often replaced with a new one. Most tuners carry new strings with them and can match up the correct size. Strings size goes from size 13 up to 22 with increments of 1/2 sizes. The tuner has a gage to determine the size of the broken string which needs to be replaced with the same size. In the treble section, a string/wire starts at a tuning pin and loops around a hitch pin, at the other end, and comes back around another tuning pin. In other words, if one treble string breaks, you have actually lost two strings.
A new bass string is more expensive and must be custom made based on measurement specifications that the tuner/technician takes to order the custom string replacement. After a string is replaced with a new one, the new string will go out of tune quickly. This either requires return visits to keep tuning up that one string, or some tuners will leave the replaced string muted (not sounding) and plan to remove the mute/felt at the next regular tuning. String splicing does not have this problem which makes it a good alternative if the broken string is in good condition and can allow this splicing process.
Q - What are "false beats"?
A - A "beat" is what you hear when the vibrations of one string slightly exceed those of another which is the case when a string is slightly out of tune compared with another. Listening to two strings when one is vibrating at 440 beats a second and the other at 439, will result in one beat per second as the vibrations of one string overtakes the other. Occasionally a piano has what is referred to as "false beats". In this case you can listen to a single string by itself that sounds similar to hearing two strings that are out of tune with each other. Most pianos have some strings that are not pure sounding. But if they are not extreme this may not be noticed and the tuner may even be able to compensate in the tuning process or by addressing the cause.
Q - Why do some keys stick or not work at all?
A - In some cases, the actual key sticks and does not move properly. This is a more common problem when you notice "sticky keys". There is a pin under and front of the key and one at the center of the key. One or both of these can become tight, due to wood swelling, or corroded. In some cases the key can actually break. In other situations, there may be a broken or sticking part in the action mechanism. The tuner / technician can determine the cause and correct the problem. Much of the time, sticky keys are not difficult to fix. But there are situations where part break and must be replaced causing the need for parts and additional repair time to dismantle the piano to replace or repair the broken part.
Q - What does a piano technician do in addition to piano tuning?
A - The technician can repair technical issues that keep a piano from functioning as it was designed. For example the piano technician is trained to handle necessary repairs and adjustments so that:
all piano key respond to the touch quickly and are felt by the slightest press of the finger
each key resets itself quickly and completely for the next strike of the key / string
the tone of each note is similar (without some being bright and others weak or dull)
keys are all level at the same key height
hammers start to travel toward the strings, without delay, as the key is pressed
dampers stop the sound immediately and quietly when the key is released
each pedal should function as designed and be free of rattles and squeaks
missing, worn, or broken parts are fixed or replaced
a humidity control system is installed in the piano if needed