（一）黄金分割也叫分线段成中外比。意思是将一线段分割成长短两部份，使得长的一段与整线段之比等于短的一段与长的一段之比。由于如果把一条线段分成中外比，用所得的长、短两段作为矩形的邻边，则矩形的形状很为美观；在音乐里， (1) The golden section is also called the split section into the Chinese-foreign ratio. This means that a line segment is divided into two short segments, so that the ratio of the long segment to the entire segment is equal to the ratio of the short segment to the long segment. Since if a line segment is divided into Chinese and foreign ratios, the resulting long and short segments are used as the adjacent sides of the rectangle, the shape of the rectangle is very beautiful; in music,