Strength and weakness are the laws of beats. Beats are divided into single, complex, transformation, interleaving and mixing. The relative time signatures are different, and the strength and weakness patterns are also different.

The common beats are as follows:

2/4 beat - there are only two beats in each measure, and the rule is: strong and weak.

3/4 beat - there are only three beats in each measure, and the rule is: strong, weak, weak.

4/4 beat - There are only four beats in each measure (but it can be divided by two), so the rule is: strong, weak, sub-strong, weak.

6/8 beats - There are only six beats in each measure (but it is divisible by two), so the rule is: strong, weak, weak, next strong, weak, weak.