For the samsung t819 is both the USB cord and memory card required? Or just the card or the USB cord? I have the card and I would like to no if the USB is required to. I don't have a card reader. I know you can put music on with just the cord, but what does the card do. If this is confusing, all I'm asking is what do i need to put music on the samsung t819 and how do you do it?