Audrey, I see Alec didn't respond to your question, but he has covered this topic many times. You are limited to the 99 folders on any SD card, but not limited to 20 files for each folder. If you want to take the extra time to load into custom memory you can gain much more storage: 20x20x99=39600 files. Actually, memory size is more limiting than the amount of folders and files, but with your large SD card, you should have a lifetime of card stuffing ahead of you. I've been editing my archives and loading the SD with custom saves and it's only 512 meg. So far, with over 500 songs saved I've filled 3% of the card and will probably get every single file I have on that card.