nashville2Just as British rock musicians two generations ago revived and updated American blues for U.S. audiences, it may be the British touch, perversely, that has boosted the music known as Americana.

A new film about Americana that premieres tonight, “Nashville 2.0: The Rise of Americana” (PBS, 9 p.m.,check local listings), might not have been made had it not been for the Brits.

“Maybe the reason this film exists now, is when Mumford won the Grammys,” says filmmaker Susan Wittenberg. “Suddenly, people were looking at a category in a different way than they did before.”

And what had once filled clubs was now filling arenas and amphitheaters.

” It is having its moment,” Carol Stein says. “It’s been around for quite a while, but it’s broken through in a way that’s just very exciting.”

The Mumford phenomenon is part of what Stein calls a “very rich communication between British roots and these musicians are from all over the country. Such musicians, she says, hail from Park Slope, L.A.,, South Carolina and Texas.

Why call the film “Nashville 2.0″ then?

Says Wittenberg” “One of the things about Nashville is that it is its spiritual home even though, in actuality, the artists many of the artists live in all kinds of other places, and that’s the spiritual home of country music as well.

“We work very closely with an organization called the Americana Music Association. They’ve been based in Nashville in Nashville, and it’s every year in September there are the Americana Music Awards,” she said. “So it was a logical place for the story to begin.”

In addition to Mumford & Sons, the film includes participation of Emmylou Harris, Rosanne Cash, Buddy Miller, the Mavericks and Shovels & Rope.