One sentence style, two sentence style, three sentence style, four sentence style, six sentence style.

1. One-sentence style: refers to the lyrics of folk songs with only one sentence, often consisting of one musical phrase. This form is simple and lively, and is often used to express simple and direct emotions.

2. Two-sentence style: refers to the lyrics of folk songs consisting of two sentences and two musical phrases. This form is often seen in narrative songs, which can express emotions and stories in more detail.

3. Three-sentence style: refers to the lyrics of folk songs consisting of three sentences and three musical phrases. This form is common in narrative songs and lyrical songs, and can express emotions and plots more abundantly.

4. Four-sentence style: refers to the lyrics of folk songs consisting of four sentences and four musical phrases. This form is common in narrative songs and lyrical songs, and can express emotions and plots in more detail.

5. Six-sentence style: refers to the lyrics of folk songs consisting of six sentences and six musical phrases. This form is common in narrative songs and lyrical songs, and can express emotions and plots more abundantly.