In each section, music alternates between strong beats and weak beats. This alternation cannot be chaotic or arbitrarily arranged. Instead, it forms a minimum beat according to certain rules to organize a section, and then cycles based on it. Back and forth. For example, when there is only one weak beat between two strong beats, it is called "two beats", which is the type of 2/4 beat; when there are two weak beats between two strong beats, it is called "triple beat", Like 3/4 and 3/8; there are three weak beats between the two strong beats, which are called "four beats", and the most common one is 4/4. Two sections are separated by a "bar line". The bar line is a thin line perpendicular to the staff, with five lines on top and one line on the bottom, which just cuts off the staff. No matter how far away the upper and lower lines are from the staff, the bar line cannot go beyond the staff. Draw two bar lines in the last section of the work, and the one on the right is thicker, indicating the end of a work or a paragraph. The beat after the bar line must be a strong beat, and there is only one strong beat in each bar, and the rest are weak beats. .

The beat refers to the combination of strong beats and weak beats. Specifically, it refers to the total length of notes in each section of the score. Common ones are 1/4, 2/4, 3/4, and 4. /4, 3/8, 6/8, 7/8, 9/8, 12/8 beats, etc. The length of each measure is fixed. The tempo of a piece of music is fixed at the time of composition and will not change. A piece of music can be composed of a combination of several beats.