You can use whatever type of chord you want to use- though using bar chords are a little more intermediate, I think it sounds better. Start by playing A and D while he's whistling A D When I was just a little boy A I threw away all of my action toys D A D While I became obsessed with Operation A D With hearts and minds and certain glands A you gotta learn to keep a steady hand D A D and thus began my morbid fascination E F#m F#m E Tore the spines from out of all of these self-help books F#m D Made myself a gun that not only shoots but looks so real E A D Yeah, it shoots through steel with rays of dark matter A D A D Rays of dark matter It's really just the same through the rest of the song. It's an amazing song and easy to learn. I hope you have fun. d:)