I suppose you are a big fan of Jay Chou. I also love his music and I agree that he is an excellent composer and singer. He however is not a good Mandarin speaker. His pronounciation is notoriously unclear. If Chinese learners want to learn Mandarin pronounciation from his songs they will find it more difficult. I am not sure if this is a good idea to learn Chinese by lyrics as the lyric structures do not follow certain rules. Perhaps someone would like to give it a try?