If you already have the folders set up, just drop the top level directory into emplode. If you have a Directory tree like this:

Rock

 +- Beatles

 |   + White Album

 |      + X.mp3

 |      + Y.mp3

Pop

 +- A

     + album

        + D.mp3

        + D.mp3

and drop the Genre directories into emplode, you will get a playlist hierarchy that looks exactly the same.

cu,
sven

Edit: Oh, before I forget to mention it: That is also mentioned in the docs.