Modifiers
A note value may be augmented by adding a dot after it. This dot adds the next lower note value, making it one and a half times its original duration. A number of dots (n) lengthen the note value by its value, so two dots add two lower note values, making a total of one and three quarters times its original duration. The rare three dots make it one and seven eighths the duration, and so on.
To divide a note value to three equal parts, or some other value than two, tuplets may be used. However, see swung note and notes inégales.
Read more about this topic: Note Value