How to get music from your computer to your dsi

Ok first your gonna need I tunes on your computer and an SD card.Open your I tunes and put your SD card in your SD card slot.Then you right click on the song you want then click on the,Create ACC File.Once its finishes creating the new music it should be either under the original song or in the "recently played".Then you drag the new file to your desktop.After that go to your computer folder.Drag the file from your desktop to your SD card file on your computer folder.Then all you have to do is put the SD card into your DSI and go to the sound app then "play with your music" and youll see the song.