After much rumouring, the way Guitar Hero DS will play has been revealed, and for those wondering what DS features the game would make use of the answer has come. That answer is every single one of them, and a bit more. The main draw of the game will be a special 4 button peripheral to plug into the DS’s GBA slot called a ‘Guitar Grip’. It will mimic the fret buttons of a normal GH controller, albeit in smaller scale. The Grip will also have a strap for your hand to make sure the DS is not rocking all over the place when you play.
Playing the game will see you holding the DS sideways - Hotel Dusk style – with the familiar Guitar Hero note highway appearing on the non-touchscreen and the touchsceren been use as a pick. Videogameszone.de have a video available, which makes more sense than I do. They also explain that it is likely the game will only be compatiable with the DS Lite due to the shape of the Gutiar Grip.