At the beginning of each piece of music, after the bass clef, is the time signature.
The time signature indicates the number of beats per bar (the top number) and the type of note receiving one beat (the bottom number). For example:
Thus in * time there must be the equivalent of 4 quarter notes per bar, e.g.:
* is the most common time signature and is sometimes represented by the symbol called common time.
Another popular time signature is ^ time, indicating 3 quarter note beats per bar, e.g.:
The ) time signature is indicated by six eighth notes per bar. The eighth notes are usually compound into groups of three, e.g.: