When Jane Espenson first wrote for TV shows in the early ‘90s, it was hard to know what the audience thought. Feedback trickled in via paper mail. It could take weeks or months to find out whether fans liked an episode.

Now it takes seconds. Espenson currently writes for ABC’s Once Upon a Time, and a recent episode included a flashback that featured a child actor who looked eerily like the adult star. When the episode aired, Espenson scanned her Twitter feed and found that—bingo—the casting decision was a hit.

“The instant she went onscreen,” Espenson says, “Twitter was flooded with people going, ‘How did you do this? She looks perfect!’” The writer’s 64,000 followers are vocal on all fronts: They send her both withering critiques and frantic suggestions for future story lines. All told, her followers @reply her about 150 times a day.

For decades, TV writing was a solitary pursuit, with the writers alone in a room. Social media has transformed it. The process is now more like playing in a live band, with an audience cheering, booing and hollering out requests. This is true across the cultural waterfront. As artists in all media go social—from novelists to painters to musicians—the very practice of their craft is becoming public.

In an online world, all art is becoming “live”—and pretty complicated, too.

I first got a whiff of this dynamic a few years ago while talking to Jonathan Coulton, a songwriter who was composing and posting a song a week. The first few tunes received middling attention—then one abruptly became a massive pass-around hit. “So you wonder, should I write another song exactly like the last one?” he says.

If the audience speaks, do you listen?

It’s impossible for artists not to be swayed emotionally by their networked audiences these days.

The first answer I hear from most artists—including Coulton and Espenson—is no. Numbly chasing the crowd is fatal to unique artistic vision. Chloe Neill, author of a best-selling supernatural romance series, recently killed off a beloved character and faced passionate zOMG online fan response. But she hasn’t let it affect her upcoming novels: “I’ve tried to stay the course of the arc that I’ve had in my head and not be swayed by opinion,” Neill says. Try to please everyone and you wind up pleasing no one.

Yet the thing is, the flip side is also true. These same creators grudgingly admit it’s impossible not to be swayed emotionally by your networked audience—and perhaps not even creatively wise.

Kurt Sutter, creator of the TV show Sons of Anarchy, is famously combative online, hurling insults at critics and fans alike. But, he admits, “I’d be an idiot” to ignore signals from the audience. When he cast Stephen King as a character, they loved it, prompting him to try more “off-the-hook casting” like David Hasselhoff and Ashley Tisdale. “It’s like workshopping in theater,” he adds, or like the old days of shooting a comedy before a live audience, when producers could tweak a scene if it fell flat.

Nor does fan input necessarily lead to bland art. Crowdfunding sites like Kickstarter require artists to nakedly curry favor with their potential audiences. But this hasn’t killed risk-taking; on the contrary, Kickstarter funders routinely support high-concept, arty material—and often continue in conversation with the artists. Espenson and her colleague Brad Bell used Kickstarter to crowdfund $60,000 for Husbands, a quirky web comedy about an accidentally married gay couple. (Then, naturally, they began documenting the production in tweets and blog posts.) Obviously, not all artists want to perform “live.” Literary novelists tend to wince at this stuff; many prefer the monklike garret.

But for creators who do migrate online—by desire or need—new skills are necessary. I think the best training is to study the lives of leading stage actors or even stand-up comics. Those performers understand how to read an audience and play off its energy but ultimately stand apart. It’s an old skill.

And now a modern one.