I'm going to guess that you made that music playlist before you added those songs. So, all you have to do is add the new songs to your playlist. There should be an easier option though, like 'adding new songs to old playlist' , and then it will add the new songs to your old playlist. And maybe an option to either randomly mix it, or put it after your old playlist. If you made that playlist, and it's only recognizing the 420 only, then that's odd behavior. Perhaps you never added the songs from the microsd I'm not sure.