mp3 playlists

What we really need is a change in the way MP3 players work as far setting up playlists. What if you could combine playlists with the shuffle feature so that after any particular song you have a separate list of songs that will play after that particular song. Then it would be nice if you could set a specific fade point between the two songs. This way it's like having a semi-random DJ. Maybe I'll go code my own that works this way and get a software patent on it.