A piano has over 20,000 parts and is a very complicated invention of the 16th Century (Italy, circa 1600 AD) but it is a long journey from there to the modern piano which we see today.
Do you know how many tuning pins are in one piano? Tuning pins tie piano strings to pin blocks which are connected to the sound board.
Did you guess 88 pins, since there are 88 keys in a piano?
There is just a single string on some notes but most notes have two to three strings per note. There are some slight variations in the number between different manufactures, but on average a piano has around 220 strings in total!
When your tuner comes to tune your piano, they have to adjust the tension of each pin/string. If the note has more than two strings, they need to mute the others to hear the string that they are tuning. It is a very delicate job, so the next time your tuner comes to tune your piano, try to be as quiet as possible or just leave the tuner alone with the piano!
When the piano has been tuned, the tuning pins are twisted by the tuning hammer to get the correct pitch. If they’ve been twisted enough times, the holes get slightly bigger, and when the holes get bigger the tuning pins won’t be able to hold their position due to the high tension of the strings. At first the tuner will be able to tap the pins into the pin block. This is a temporary fix. But soon enough, you may need to get bigger pins installed.
Pins come in many sizes, ranging from size 0 to size 5, (smallest to biggest). Depending on how loose the current pins are, new pins should be two to three sizes bigger. After installing new pins, you may need several extra tunings. Also, when pins are replaced, they are always at a slight angle, never simply 90 degrees, and coiled a specific way. Believe it or not, there are many more tricks and rules in this process!