The meter of work is indicated at the beginning by two numbers, one above the other: the lower indicates the chosen unit of measurement (half-note, quarter-note, etc.), while the upper indicates the number of such units that make up a measure. In simple times, such as 2/4, 3/4, and 4/4, each beat is normally halved to form eighth-notes, etc. In compound times, such as 6/8, 9/8, or 12/8, the basic beat is grouped into threes to form dotted notes.
In faster tempos, musicians can regard these dotted notes as the actual beat.
The time signature, four beats per measure, is called common time and indicates 4/4 time, while 2 beats per measure or cut time, indicates the generally faster 2/2 time.