A full piano keyboard has 88 keys. The distance or
interval from one key to the next is called a halfstep. Playing each note in the pattern of 12
repeating keys is called the chromatic scale.
Each letter of the music alphabet will occur 7 or
8 times throughout the range of the keyboard.
All the keys that have the same letter name
belong to the same pitch class.
Different naming systems exist for identifying a
specific key. One of them is called
Scientific Pitch Notation.
In Scientific Pitch Notation a number is assigned
to each octave based on the frequency or exact
pitch of each key.
The system is based on the hearing range of a person
and begins by adding 0 to the letters rather than 1.
The number is increased each time a new C occurs.
That is why the piano begins with A0 and B0.
Middle-C is called C4 in Scientific Pitch
Notation. If you are sitting in the middle of the
piano bench it is close to your nose.