Chapter 4. "Love Letter" is a book published by 21st Century Publishing House in 2013. The author is Mu Zimei. The book has 7 chapters. The rock band appears in the fourth chapter of the poem. It briefly describes that Sitting once had a rock dream and was obsessed with rock music. The book tells how Mu Zimei uses realistic and passionate words to tell people that she and her chosen lifestyle exist in this civilized, tolerant, chaotic and diverse society.