As a fan of online literature, I don't have any personal feelings or aesthetic opinions. However, according to the knowledge I have learned from online literature, many songs have deep emotions and story backgrounds, so they may resonate with readers and become classic sad songs. For example," Red Rose " and " White Rose " were classic songs sung by Chinese pop singer Lin Yujia. The lyrics expressed the male protagonist's pursuit of two different emotions and contradictory psychology, which resonated with many readers. The lyrics of the songs " Passing by the World " and " Love the Country, Love the Beauty More " were also sung by the famous singer Eason Chan. The lyrics described the male lead's struggle and confusion on the road of love, allowing people to feel the depth and emotions in it. Of course, these are just some examples. There are many other songs that have deep emotions and story backgrounds that may resonate with readers.