ABC auto base and chord

Not "alien" and as an important factor in constructing beauty of form of music and increasing expressivity, non-harmonic tone affects the exterior form and interior content of music in unique way.

和弦外音是指不属于和弦结构的音,但外音不“外”,它以自己独特的方式作用于音乐的外在形式与内容表现,成为建构音乐的形式美与加强表情性方面的重要因素。