Just when I thought I was starting to understand... I'm on 4.0.4 and have about 360 songs in my music library, which is on my external sd card. However, when I flash CM10, my music library is reduced to 35 songs, which is in Internal. The only thing on my external card is BeWeather (according to ES Explorer). Panic. I thought my library was safe as long as it was on my external card. Fortunately, when I restore back to stock, my music library is back intact on external, right where I left it. Phew! I don't know what all happened there as I obviously still don't understand memory. Phone storage. USB storage. Internal memory. External card. Partitioning. Without the luxury of a PC, how to keep my library intact throughout flashing other ROM's? Thank you. Edit: I figured it out. Thanks everybody.