Within each measure, there are two distinct beat values: a binary one and a ternary one.
Example
means five eighth notes per measure.
Let us group the eighth notes by three and two:
There is thus a ternary ("long") beat and a binary ("short") beat.
Some of these time signatures come from Renaissance rhythms, where hemiolas (grouping by two instead of three) were used to structure the musical phrases. Complex time signatures are also found in Central European folk dance music.
