Research
Technical differences between the piano and the Hammond organ
To understand the distinctive approaches to playing the piano and the Hammond organ, it is important to gain insight into the ways these instruments are built and how the sound is created.
The piano was invented by the Italian harpsichord maker Bartolomeo Cristofori in Padua in 1700.1 Though the modern piano is the result of centuries of technical refinement, the basic mechanism has changed surprisingly little since Cristofori's day.
In a piano the string is struck with a felt-covered hammer. When the performer presses a piano key softly, the hammer will strike the string slowly, making a soft sound. If a performer presses a key hard, the hammer strikes the string quickly, resulting in a loud sound. This is why Cristofori called the instrument a "pianoforte," literally a "softloud." "Piano" is a contraction of "pianoforte" and just means "soft" in Italian.
Three separate assemblies of the one-hundred different parts are involved in getting the force of the pianist's finger from the key to the string: the key assembly, the wippen assembly, and the hammer assembly. The key is basically a straight piece of wood that strikes the wippen assembly. The complex wippen assembly transfers the key's force to the hammer, "throwing" it towards the string. A remarkable feature of the piano mechanism is that, because the hammer is thrown by the wippen assembly, it is actually completely out of the pianist's control when it hits the string.
When the piano key is pressed, a "damper" or mute is lifted off the string, allowing the string to sound. When the key is released, the damper is replaced, muting the string. This way a note only sounds so long as its key is pressed.
The latter goes for the Hammond organ as well, but while the sound of a piano string dies out eventually, the Hammond tone keeps on going at the same volume.
