Note value
A note value may be made longer by adding a dot after it. This dot adds the next briefer note value, making it one and a half times its original length of time. 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 length of time. The rare three dots make it one and seven eighths the length of time, and so on.