Go to the piano and quickly tap your finger a key. Hit so that the finger bounced like a ball. Get short, very short sound.
Now press and hold your finger on it. The sound will be much longer, gradually fading. If you simultaneously press the right pedal, the sound will be quite long. Even if the finger is removed, it will be loud to reach...
So you met one of the basic properties of sound, which is called duration and depends on the duration of the vibrations of the sound source.
Duration in music are indicated by the system icons. The main symbol is a whole note is equal to time in four quarters. Here's how it looks: 
. It is divided into smaller fractions: half, or, simply, half (
); a quarter (
); eighth (
); sixteenth (
) and so on.
There is appropriate in duration icons for pause-pauses in the sound.
The duration of pauses
If the duration of the note or rest should be increased by half, to her right is credited with a point. For example, the sound must reach three quarters (half and quarter) is represented as: 
; sound duration in three-eighths: 
.
Extra long notes
There are also special "odd" duration - triplets, quintile and so on, that is the sounds, which on one unit, for example, half or quarter, accounting for, respectively, three, five and so on, They are written like this: 
or in kind.
