There's two media players on the RT. One is in the File Manager (tools/mass storage). With that one, you can browse and play your .mp3 files, but if you hit the back button, the music will stop playing. So even looking over the file list will stop the music. The other "Media Player" (in the Main Menu) will let you hit the back button and see the list of songs without stopping the music. But if you try to do anything else, you'll have to stop the music and exit.