Once upon a time, the reach of a play or musical was contained by the four walls within which it was playing, and the seating capacity that was offered within them.

Some shows, of course, may transfer between the West End and Broadway, or vice versa. For example, Broadway’s Memphis is about to cross the Atlantic to a West End opening at the Shaftesbury Theatre in October, and traveling in the other direction is the National’s The Curious Incident of the Dog in the Night-time, due at Broadway’s Barrymore Theatre from September 10. A lucky few shows may go on to an international life in replica productions around the world, like Cats, Les Misérables, The Phantom of the Opera, Mamma Mia! or War Horse. But those have been exceptions rather than rules.
And while the essence of theater will always be in its liveness, it is now proving possible for that essence to be preserved while potentially reaching hundreds of thousands of people at once.

Last November, for instance, Britain’s National Theatre celebrated its 50th anniversary with a one-off gala performance, staged at the Olivier Theatre, where an invited audience of just 1,160 people saw it. (You can double that number if you include the public dress rehearsal the day before.) But in fact many millions more saw the show for free, on U.K. terrestrial television and via live relay into cinemas elsewhere around the world via the NT Live initiative, for the price of a movie ticket. NT Live, which was introduced exactly five years ago, in June 2009, with the broadcast of the NT artistic director Nicholas Hytner’s production of Phèdre starring Helen Mirren in the title role, may just prove to be the most significant legacy of Hytner’s time at the helm with executive director Nick Starr.

When I said as much in another feature last year, Starr enthusiastically concurred: “You’re right — Nick and I do think it’s probably the most significant thing we’ve done,” he said to me. That’s because it has so comprehensively changed the game plan for how theater can reach more people simultaneously around the world than was ever thought possible.

Since its launch, the NT Live’s broadcasts have been experienced by more than 1.5 million people in 1,000 venues around the world, from North America to Australia, Bulgaria to the Bahamas, Peru to Poland, and Sweden to Switzerland.

And The National has also generously not kept its toys for itself; it has also offered the platform to other companies, including the Donmar Warehouse, which in January broadcast its new production of Coriolanus, starring Tom Hiddleston in the title role, via NT Live. It played in a theatre that seats just 250 people, so demand for it was always going to outstrip supply. Likewise, NT Live also broadcast the Manchester International Festival staging of Macbeth starring Kenneth Branagh in the title role; in that case, it ran for just a fortnight, though the production is currently being reprised at New York’s Park Avenue Armory through June 22. Helen Mirren has also returned to NT Live with a live screening of her last West End run, as the British monarch in The Audience earlier this year (due to be reprised in Encore screenings this month).

But neither has The National confined NT Live to its limited-run shows. Earlier this year it broadcast War Horse live from the West End’s New London Theatre; the show has already been seen globally by nearly 5 million spectators everywhere from Broadway to Berlin, and is even now on a new U.K. tour, but here it saw it grow its reach even more swiftly in one night. (And far from potentially cannibalizing the audience who might see it in the theatre, it may well encourage them to see it there again; certainly the release of the film version of Les Misérables gave the West End run a definite boost.)

The National’s recordings of its shows via NT Live is also creating a brilliant archive, and it’s also offering continuing encore screenings of Danny Boyle’s production of Frankenstein starring Benedict Cumberbatch and Jonny Lee Miller, and Hamlet with Rory Kinnear in coming months.

There’s clearly a new hunger and appetite for seeing the best that the West End and National Theatre can offer far beyond their own geographical reach. But how did it all come about? David Sabel, the American-born head of digital for the National, who trained originally as an actor in Chicago and subsequently at Jacques Lecoq’s famous physical theater school in Paris, came to set it up by a mixture of what he calls “serendipity, good timing, and maybe fate.”

As well as acting, he’d also worked as a chef, and then earned a business degree at Cambridge University in the U.K. As part of his dissertation for the latter, he met Hytner. And on the same day they met, Hytner ran into his chief operating officer Lisa Berger and they talked about the screenings that New York’s Metropolitan Opera House were doing. Hytner told her he’d just met someone who might be the right person to look into it for them. “My combination of skills suited me well for doing a feasibility study on it — though I have to admit that I went into it skeptically, thinking it was the antithesis of what theater is about and wondering if what worked for the opera could work for the theater.”

After spending two months researching what the Met had done, and thinking of the implications for theater, Sabel wasn’t sure that it would even work — “but if it could be made to work, wouldn’t it be most incredible win for access, especially for theatergoers in the U.K.? We could extend access to National Theatre productions for people who would otherwise not get the opportunity, whether because something was sold out and they could not get a ticket, or they lived too far away.”

But the most important thing was, he says, “to be able to honor the artistic integrity of the show and still make sure that audiences had a great experience.” Once Helen Mirren was confirmed for Phèdre, it enabled them to launch it with a splash. “But we knew it couldn’t be a one-off, that we needed a pilot season to test other shows. If Helen wasn’t in it, would it still be a success?”

Phèdre, it turns out, “went brilliantly — it was an artistic success and it caught the imagination of people.” Meanwhile, the National quickly set about building its cinema network: “We started with 270, with about 70 in the U.K. and 200 outside; it has now grown to more than 1,000, 530 of them in the U.K. When you think that a big film release like X-Men might go to 500 screens, it’s amazing that a National Theatre show goes to the same number. It was recently said in the trade magazine Sight and Sound that more people saw [the Donmar Warehouse production of] Coriolanus than the Ralph Fiennes film of it.”

NT Live now goes to some 35 countries around the world — always live in the U.K. and most European countries, and to North America and Canada on the same day but delayed for time zones. Elsewhere, the broadcasts are sometimes shown during a staggered time period of a few days.

Now Sabel’s job also encompasses building relationships with other broadcasters, working with the BBC, for instance, on their Arena documentaries on the history of the National last year, and also coproducing a feature film version of the hit National Theatre musical London Road, whose U.K. distribution he will head up. “Our film partners looked at the reach NT Live has, and it was a natural fit.”

It is, concludes Sabel, “an incredibly rewarding program to work on. Although it is never a replacement to going to the theatre, if you can’t get there, it’s a really great way to see it. And it’s a great thing for the brand and the organization to be able to share what we do so widely.”