I could post a disastrous image of how the composer, Ron Grainer, would have made it if he did it. He is credited as the inventor of the theme, but he really only came up with the oo-ee-oo part, and just the notes of it at that. Then he went on vacation and let Delia Derbyshire make the theme for him. When he came back, she had made this. He was so impressed that he didn't touch it and used it as is. Years later, he made his own version, which is how he would have done the theme. I think Doctor Who would have been cancelled if they ended up using that theme though...