I use my SGS3 as my music player. Just connect your S2 to your PC via USB and mount it as a removable drive. Then using Windows File Explorer (I assume you have a PC), just copy your music files to your S2 into the Music folder. Note that when I tried this, I get a message asking me if I want to do some sort of file conversioni. Say NO to this. I find the songs will instantly appear in my music player.