What is tuning?

Tuning comes down to adjusting the tension of the piano strings until they are in harmony with the notes around them. While on the surface that sounds like a simple task there is much more to it than meets the eye.

Most pianos have 88 keys, and so it may seem reasonable to conclude that there are 88 strings inside the piano. That assumption, however, would be wrong.
While the exact number of strings will differ from model to model, there are over 200 strings in every piano. The technician will have to adjust each of these strings. Not only to ensure that the piano is on pitch but also to ensure that each note is in harmony with the notes that surround it.
Other than the number of strings, the string tension and the tuning pins’ stability play a factor.
Loose tuning pins will mean that as the technician tries to tune the piano, the loose pins will move and the string will once again slip out of harmony.
Furthermore, in modern pianos each length of piano wire usually makes up two strings, which are separated by a sharp bend in the wire where they are anchored. These strings can either sound the same note or are part of the note next to them. If they are not part of the same note it means that one half of the wire has to be tuned half a step higher (or lower) than the other half. Which would of course mean that these two halves are held at different tensions from one another.
The tension of the strings in a piano is important. It does more than making the piano sound good  A440 has been standard concert pitch in Britain since 1939 and worldwide since 1955. Ever since then, pianos have been designed for their strings to be kept at A440.
The tension on a piano’s strings average on 90 kilograms each. This is why strings will stretch even if the piano isn’t played, and why it is important to tune the piano frequently even when it isn’t in use.

Tuning a piano regularly will keep it from falling far out of pitch. The longer a piano goes without being tuned the further it falls out of pitch. The further out of pitch it is, the more difficult it is to get the piano back to its proper tension levels. A piano that hasn’t been tuned for more than a year will very likely require one or more pitch adjustments to. A pitch adjustment stretches the strings of a piano back to their proper tension levels or releases string tension. After the pitch has been adjusted there is a 2 week period in which the pitch adjustment needs to settle with the bridges. Only after the pitch has been adjusted and the strings have settled on their new tensions can a stable tuning be achieved.

If a piano has gone very far out of pitch it may take more than one pitch adjustment. Though strings can break for many reasons, the most likely time for them to break is during a pitch adjustment. This is because the process of stretching the strings puts them under intense pressure and they might not be up for the task.

No technician sets out to break strings, but it is a consequence that one should be prepared for.

Regular tuning will contribute to a longer life for your piano. Regular maintenance will ensure that your piano does not fall into disrepair. A technician will be able to spot any problems that you may be unaware of and keep them from becoming a larger problem in the future.