It's not possible to delete exported Songs from the SD card while it's inserted in the TD-17. If you recorded Songs using the TD-17's Song Record feature, and they've been saved by exporting them to the SD card, they must be deleted off of the card using the computer. (Drag recorded songs from the REC folder on the SD card to the trash). This is the case for songs that you may have transferred from the computer to the SD card as well.