I'll try to get hold of some Theresa Teng recordings.
Yes, I had the same experience - nowadays the texts of thousands of Hokkien poems and folk-songs can be found on the internet. For me, it's a bit frustrating that each song can have so many different versions (or that even just the *same* word can be written in so many different ways), but I suppose I accept that that is how it happens in an oral tradition, and when the writing of Hokkien in characters is not standardized.
Sim