The AA won't recognize an external drive connected by a wire yet. It has to be a USB key plugged into the jack directly. Ian implied this will change in the future though. In the meantime you will have to get a high capacity key (or multiple, as there are multiple slots) and copy your music onto them. I have one of the tiny Sandisk 128 Gb keys and it works nice, and you can still close the door it's so small.