Many writers fear tone. They want to be able to take the story anywhere and resent the fact that the audience might not be willing to follow along after them. But good writers can use tone to their own advantage. Tone is your tool for managing expectations.
Let’s go back in time and change just one thing about the movie Star Wars, before it gets released. What if, instead “A long time ago, in a galaxy far, far away…” the opening crawl had started with the line: “It is the year 25,172!” Even if the rest of movie had stayed the same, I doubt it would have been as big of a success.
That opening line is brilliant. It de-fangs the audience. It says, “Holds on there, buddy, this may look like science-fiction, with space ships and lasers and robots, but it’s not. It’s a fairy tale. So don’t expect a lot of time-travel paradoxes or super-computers. Instead, you should expect princesses and swords and magical mentors.” Lucas was managing our expectations. He was establishing a certain tone, before we in the audience could start making false genre assumptions that would have just left us frustrated.
Of course, once you establish a certain tone, you have to deliver. No matter how bored you get, you can’t condition the audience to expect a certain kind of emotional pay-off and then arbitrarily deliver something else. The most infamous example of this in recent years was Hancock, which abruptly switched from jokey satire to grim-and-gritty epic halfway through, but it wasn’t alone. Most recent failed blockbusters, from Superman Returns to Indy 4 to the Star Wars prequels, suffer from this problem. Out-of-control directors randomly mix adventure with drama with horror with slapstick, annoying everybody and pleasing nobody.
Once you establish a tone, you make a promise to an audience. That promise can been a harsh taskmaster, but it can also reassure your audience that you know what you’re doing and you’re going to deliver. As long as you keep that promise in the end, you can roam the galaxy at will while you’re getting there.