Blues is the ancestor of jazz, rock and gospel songs. It was originally a 12-bar musical form sung by early black slaves in the United States to express their moods. There were a lot of blues sounds when singing or playing ( The application of Blue Notes makes the music full of depressive and disharmonious feelings. This kind of music sounds very melancholy (Blue). The blues school can be divided into the following groups: 1. Delta Blues: Mississippi Delta Blues 2. Texas Blues: 3. Chicago Blues: 4. Country Blues: 5. Rythm Blues: Rhythm and Blues (R&B) 6. Jazz Blues: By the way, Jazz Blues introduces a blues-type song, "Longing for Love" by Yang Zongwei