My last post about Mandarin was related to tones. Tones convey important meaning but they are a hindrance when you want to sing, since songs have their own tones. The Chinese solution: ignore the tones.
A popular Chinese song, 月亮代表我的心 (The Moon Represents My Heart), demonstrates this. This song, originally performed by Teresa Teng, demonstrates it in action. Here is the same song, performed by Leslie Cheung. It's interesting to note that Mr. Cheung is speaking in Cantonese to the audience before singing the song in Mandarin. His pronounciation of the words is slightly different than Ms. Teng's but that's not really suprising.
The other interesting thing about singing in Chinese is that some of the words are mis-pronounced, at least in this song. The word 的 is normally pronounced 'de' but both singers pronounce it 'di'. That sounds odd to me but since I don't listen to Chinese music I can't say if it's commonplace or not.
For more information about 月亮代表我的心, check out this link.