The piano keyboard is laid out in a structured fashion with notes repeating themselves every twelve keys. When a key is pressed, a hammer strikes a series of strings (one, two, or three strings depending on the note's position on the piano) and a pitch sounds. The pitches move from low to high, left to right. In other words, when you sit at the piano, the lowest pitch will be to your left and the highest pitch will be to your right. If you're sitting at your piano now, strike the highest and lowest keys. You will hear a distinct difference between them. Modern pianos and most professional digital pianos contain eighty-eight keys.
The keys on a piano are white and black and they each have letter names. The white keys are: A, B, C, D, E, F, and G. Collectively, these notes are called “naturals.” After G, the lettering begins again with A. This A to G sequence occurs seven full times on an eighty-eight keyed piano. After these seven octaves, three additional notes remain. They are A, B, and C.
It's important to note that each key on the keyboard has been assigned a numerical name. These numbers correspond to the placement of the note on the piano. The numbering system begins with zero. The first or lowest note on the keyboard is A0. The top note is C8 since it is the eighth C to appear on the keyboard (see Figure 12-1). The twenty-fourth note up from the bottom, when counting only white keys, is middle C. This is called C4 since it is the fourth C on the keyboard (traveling up the keyboard from left to right). This numerical method of determining octaves can also applied to other instruments (e.g., violin, marimba, flute, etc.).
FIGURE 12-1: The range of the piano on the grand staff