A Brief History of the Piano
The first piano was created by an Italian named Bartolomeo Cristofori around 1700. His intention was to make an instrument with a more dynamic tone than the harpsichord, which does not allow musicians to have much control over the volume of the notes they are playing. It was originally called a pianoforte, because in Italian the terms “piano” and “forte” mean “soft” and “loud”, respectively.
Cristofori did this by changing the mechanism that causes the strings to vibrate. Whereas a harpsichord uses a plectrum to pluck its strings, Cristofori designed a system that uses a hammer that is pushed toward the string at first and then allowed to travel the rest of the way on its own momentum. This made the piano more responsive to the touch of the musician, since playing a note harder would result in a louder sound, and vice versa.
Modern pianos, though they have evolved over the years, still use the same concept. Allowing the musician to play both loudly and softly is still a core goal in the design of the instrument. At some point the strings were placed in a vertical position to save space, which led to the modern upright piano.
Side view of a grand piano action. (graphic from: https://www.pianoemporium.com/wp-content/uploads/2016/01/grand_piano_action.gif)
The design of a modern grand piano offers musicians the highest degree of responsiveness. This is due in large part to the grand piano using gravity to help the hammer return, which allows the musician to play faster and with more control. As you can see from the image above, the felt part of the hammer, which is the heaviest, is set horizontally in relation to the string. This means that once the hammer bounces off the string, gravity helps it quickly return to a position in which it can be played again.
The speed with which a note can be repeated is referred to as its repetition. This is important when gauging the quality of a piano, since better quality pianos have a higher degree of repetition.
The horizontal position of the hammer on a grand piano also makes grand piano actions feel smoother.
The biggest drawback of a grand piano is that it takes up a lot of space. In general, the longer a grand piano is the better it sounds and functions. The reason concert grand pianos are so large (they tend to be about 9 feet long) is that bigger pianos are much louder, and the longer keys allow energy to be transferred from the finger of the musician to the string more efficiently. The smaller a piano action is, the harder it is to switch between playing loudly or softly, and being able to switch between playing loudly and softly is part of the reason the piano was invented in the first place.
Here is a virtual representation of a grand piano action in action.
Side view of an upright piano action. (graphic from: https://rennerusa.com/wp-content/uploads/2017/06/main.jpg)
Upright pianos were created by taking the soundboard, plate and strings and making them vertical in order to save space. The hammer is also set vertically in relation to the string.
This means that uprights are not able to use gravity as effectively to help the hammer return to a position in which it can be played again.
Upright actions incorporate springs to help compensate for this lack of gravitational force. Even so, upright pianos generally have a slower rate of repetition than grand pianos, and are less responsive. They also tend to be on the smaller side, which negatively impacts their tone and feel.
Although uprights are, by design, not able to have the same advantages as grands, they are more practical for many players who simply want to enjoy a piano in their home. They are also common in music school practice rooms.
The average upright is cheaper than the average grand and takes up less space. In addition, the aforementioned disadvantages of uprights are not so severe as to interfere with a musician’s ability to play complicated pieces with expression. Uprights are even used for performances in certain situations.
Side view of spinet action. (graphic from: https://pianoguidelessons.com/wp-content/uploads/2017/01/dropAct.gif)
The spinet is a type of upright that was designed to save even more space. Spinets have what is called a drop-action, which means that the action was taken below the level of the keys and connected to the keys with with a rod. They take up little space horizontally as well as vertically.
Spinets offer the least in terms of responsiveness, repetition, and tone. They are very small and the design of the action means more energy is lost in the transfer between the finger of the musician and the string. The awkward design also makes them difficult to maintain or repair.
As digital keyboard technology has gotten better, spinets have been pushed toward obsolescence. A modern digital keyboard does not take up much space and has a sound that is comparable to if not better than a spinet.
Bartolomeo Cristofori created the design for the piano to give keyboardists a greater range of expression. This led to the modern grand and upright piano.
There are three main types of pianos in circulation today. They are the grand, the upright, and the spinet. The design of the grand piano offers the best tone, feel, and repetition, but is expensive and takes up a lot of space. A standard upright is less expensive and takes up a lot less space, but sacrifices these attributes to some degree. A spinet costs the least and takes up the least amount space, but sacrifices the most in terms of tone, feel and repetition to achieve this.