Or maybe it's the following moment when people attempt to answer it.
Anyone who has heard be talk about this before has heard my smug and self-satisfied response: "THEY DON'T!" And of course that's right, really. No play matters that much, in the great scheme of things. It isn't curing any disease. It's an entertainment. Yes, political plays may say something, but they often say something the audience already knows. (Does anyone really walk away from a play about genocide thinking, Gee, you know, when I walked in the door, I didn't think genocide was all that bad. But NOW . . .) I suppose I've got a somewhat nihilistic view of the theatre. I see no evidence it can change an audience or incite the response plays may have in theatre's more glorious and heady past.
The question also bothers me because the subtext isn't "What is this play important?" It's: "Why is this play important." And, as such, implies it is more important than other plays.
That bugs me. Maybe, yes, Angels in America is a "more important" play than Noises Off. But to me, it's more important because it taught me a lot about play-making. It's also the kind of theatre I'm more interested in seeing. Poll folks around the country, though, and ask whether they'd rather see a play about a gay guy living with AIDS who is seeing Angels, or a fast-paced comic romp about a bunch of actors falling down the stairs, and my guess is that, important or no, most Americans would rather cap off a long day with Noises Off. Would I? I dunno. Some days, yeah.
So this is all by way of saying "this play isn't important, or certainly any more important than any other play, because to most people theatre doesn't matter." And that's a sad thing for a playwright to say, but it's how I felt... until I spent a lot of time wrestling with the idea of "important" vs. "unimportant" plays.
Ultimately, I still believe that no play is more important than any other play, no matter how unpopular that may make me with liberal, particularly political theatre folk. BUT: here's my caveat, and here's where things get good:
Theatre is important. Here's why: unlike nearly any other form of entertainment, it FORCES us to engage with and empathize with others in an active way. My theory is that it's because there are real people there with us, and audiences can't distance themselves from that. Those are living, breathing bodies there, with FEELINGS--and they're FEELING them RIGHT NOW. I don't think movies do that, so much. It's easier to passively engage a movie, I think (maybe this is all crap, who knows), because no matter what you're so far away from it. TV may engage a bit more active empathy because it's in your living room. But a play, when done well, demands that we engage with the characters. But reality TV, the most popular genre (the fast food of entertainment), is all about schaedenfreude. It's about laughing at the real travails of others, rather than sympathizing with them. (Unless it's one of those feel-good, emotional shows where people who've suffered horrible tragedies get their homes made over. That's just using tragedy to manipulate audiences and make them feel like they've done something good, even though that's one family who got a castle with solar panels, and the world is decidedly still NOT a better place.)
A play is an act of empathy.
And empathy is not something we're all that good at, these days.
What's more, is that plays require us to empathize with people doing pretty awful things. In a way, then, a play is like an emotional workout. We HAVE to empathize with Richard III or Hedda or Hedwig or whoever, regardless of whether we like them, because the person is standing in front of us, and we're surrounded by others, and we paid all this money and found a parking space and came out in the snow and so why not?
It's healthy thing, then. And whether it's Angels in America or Noises Off, we're still empathizing. We empathize with Prior and we empathize with Poppy. In different ways, and for different reasons, but we give a damn. And that's a good thing.
(Of course, this supposes the play is good, the production works, and the actors are talented. Nothing is worse for an audience, and produces LESS empathy than a shitty production. But more on that later.)
See Paula Vogel talk about negative empathy, here: