After a lot of search (ie. 2 hours less sleep and 3 hours no work in the office), I found following comment: "在众多论坛流传的所谓杜普蕾大提琴曲《缠绵往事, 其实是《神秘园》第五辑《Earthsongs》第9轨的小提琴曲 "Silence Speaks".
I think that comment is right, you can find it by searching with "Secret Garden"+"Silence Speaks".
Again, thank you for sharing, and I still think it's beautiful.
