That's fine. Thanks for replying. I know chromatic mediants are a common technique in film scores, but have no knowledge of octatonically related keys. Maybe @Henry Ng Tsz Kiu was referring to a similar concept when he said the technique was common in film music.
Hello I'm relatively new to composition. What are octatonically related keys? I know what an octatonic scale is, but I don't know how it is used. It's hard to imagine how an eight note works when music theory teaches you to think in seven note scales. If anyone could explain what octatonically related keys are, I would really appreciate it.