Sculptures, paintings and other art forms are frozen in the space, making it clear at a glance. When we appreciate art works, we first see the whole art work, and then we taste its details. Music is different. Music has to unfold and flow in time. When we appreciate music, we start from the details, from the part, until the whole song is played (sung), it will leave us with an overall impression. It is impossible to obtain a complete musical image by only listening to individual fragments in a musical composition. Therefore, the art of music is also an art of time.