A Study on The Piano, a Favorite Hobby of Mine

I chose to do a more in depth study of the piano because playing the piano is one of my favorite hobbies. I’ve played since I was six years old, and some of my earliest memories are dancing with my sisters as my mother played the piano. Throughout my life I’ve had a chance to play the piano for seminary, church, my school choir, several classes, and two high school graduation ceremonies. As I learned to play the piano I learned the basics of how it works, but I’ve always wanted to learn more about what actually happens inside.

The piano is a surprisingly complex instrument for how easy it is to just push the key and make sound. To make one note, “The player presses on a key that is one end of a lever that sets the action into motion. In normal playing, the piano hammer is propelled toward the string at speeds of typically 1-4 m/s. The hammer is released from the action just before it collides with the string, traveling freely when it collides and then rebounds from the string. ” There are many more parts to the piano besides just the hammer, string, and key though.

Much like on a violin, there is a nut and a bridge that determine the length of the string. The length of the string determines the pitch perceived. The nut is attached to a pinblock, on top of which there is a tuning pin. The tuning pin is what is turned when someone tunes the piano. The string is wrapped around the tuning pin. When the tuner turns the pin, it tightens or loosens the string, changing the tension of the string and thus the pitch. The other end of the string is attached to the hitchpin, which is attached on top of the rim or case. The soundboard is attached inside the rim or case, and the bridge is fastened on top of the soundboard.

When the hammer after being struck, of its own inertia, travels and hits the string, a sound wave is created. “At this point the strings start vibrating; the vibrations are carried to the bridge which transmits the vibration to the soundboard which amplifies the sound.” The soundboard acts much like the soundboard on a guitar, in that it amplifies the sound and contains wood resonances. There are also air resonances inside the piano because it is mostly hollow, just like a guitar.

Inside the piano, behind the key, there is also a backcheck. On the hammer there is a catcher. When the key is held down, the backcheck latches onto the catcher and holds the hammer in place. As soon as the key is released, the backcheck releases the catcher and the hammer returns to its normal position. This happens within a fraction of a second, which is the reason pianists are able to play the same note over and over again very quickly.

Pianos often have more than one string per note. Low bass notes can usually be produced using one string, but the higher strings will have two, three, or even four strings.1 Why is this the case? By using two strings of the same length, but striking them at slightly different places, each string has a slightly different timbre. On harpsichords this is especially obvious, but on pianos those different timbres are more closely related and combine to create a full, very rich sound.

One thing I found interesting is that pianos are almost never sold as antiques. “While restoring a fine piece of furniture usually involves a craftsman restoring the finish, this would only be the starting point with a piano. The piano is a complicated mechanical marvel involving thousands of moving parts, all of which are subject to wear and deterioration. Restoring these many parts to their original condition is a major undertaking for a skilled piano technician, requiring many, many hours of labor.” 2 Pianos do not play nearly as well when they are old, simply because there are so many different parts that so easily become damaged over time. For example, the felt on the ends of the hammers in the piano becomes ineffective over time because it is so compressed from hitting against the string. The felt contributes to the timbre of the sound when the piano is played. If the felt is soft and plucked, the piano will have a warm and rich sound due to less high formant frequencies. If the felt is flattened and hardened, the piano will have many higher formant frequencies and will thus have a sound that seems too bright. When the tuner comes, he will usually pluck the felt so that it will perform its intended function again. However, if the piano is neglected for a long time and the felt is never plucked, it will become entirely useless and irredeemable.

There are two main types of pianos: smaller models (upright, console, and spinet) and grand pianos. In the smaller pianos, the strings are arranged vertically. In the grand pianos the strings are arranged horizontally. “Large concert grand pianos have bass strings about 2 m long while the bass strings in a small spinet are of the order of 1 m in length.” Grand pianos are generally far more complex than the smaller models, and some even have an extra pedal that affects the sounds produced. Grand pianos provide more precision and allow the pianist to have more control. The upright piano is a compromise. They are almost always cheaper than grand pianos and are a lot smaller, thus fitting more comfortably in a normal-sized home. While grand pianos are very nice, most pianists are not at the skill level where having a grand piano instead of an upright makes a noticeable difference.

Why are grand pianos the shape they are? They are “wing-shaped” to accommodate the string lengths. “If we assume for simplicity that all the strings in the piano have exactly the same diameter, density, and tension (which would be only a very rough assumption for the string diameters), then the length of the vibrating portion of the string should increase by precisely a factor of two as one moves an octave toward the bass.” This means that over four octaves, the lowest pitched string would be 16 times as long as the highest pitched string. Since the strings are arranged from longest to shortest (going from left to right), the piano has to be shaped almost like a triangle to accommodate the lengths of the strings.

Although playing a note on the piano is far less difficult than playing a note on the bassoon or the flute, the piano is extremely complicated on the inside. The numerous parts inside the piano have to function and be shaped exactly right for the piano to play properly. The shape of the entire piano itself also contributes to the sound produced by holding the strings in the right way. The piano is far more complex and interesting than most people realize.