It turns out that PopBot is an amazing music refresher. Not only do you get the latest hit songs without any work at all, but it also keep refreshing your old music with new.
How it works: Select a few music genres/radio stations and let the PopBot app do its magic. Next day you will have a lot of music saved as mp3 songs. And the app keeps refreshing in the background when you are asleep.
The best part is that the songs are saved in your Android phone as mp3 file. You can use these files as you do with any other mp3s.