I bet one of these conversations will be familiar to you. If you spend any time thinking about new audiences for performing arts, I bet both of them will...
Person 1: What should we have for dinner?
Person 2: Anything but pizza!
Person 1: OK...anything more specific?
Person 2: Nope. Anything that isn't pizza is fine with me.
Person 1: Who is our target audience for this production?
Person 2: Anyone who has never been to Shakespeare before!
Person 1: Ok...anything more specific?
Person 2: Nope. Anyone who hasn't been to Shakespeare before. That's who we want.
In both conversations, Person 2's answer is a fine place to start. But that's just it: it's a starting place. There's a lot of unpacking and exploring that needs to happen before you've got anything you can work with.
Since everyone has been a part of Conversation A—probably on both sides at one point or another—let's look at that one.
I'm sure you can imagine the next few lines and the frustration that will come from poking and prodding to figure out what dinner plan will make everyone happy. Skip a few steps ahead and perhaps dinner will be out at an Indian restaurant. Great. That's definitely not pizza, but looking back on the choice, would you say the characteristic that best describes the Indian restaurant is its not-pizza-ness? Doubtful. Is there a category of Yelp reviews for Not Pizza restaurants? Negative.
I'm sure you see where this is going.
It's totally fine to say you want to target people who haven't been to Shakespeare (or the symphony, or the opera...) before, but know that this isn't a final answer for a marketing plan anymore than "not pizza" is a final answer to what's for dinner.