It has been more than 16 years since the country music industry effectively shunned the Dixie Chicks because of lead singer Natalie Maines’s criticism of President George W. Bush during the invasion of Iraq, but the incident still provokes strong feelings.

That’s why many viewers were surprised when the controversy wasn’t covered in Ken Burns’s “Country Music” documentary, a 16-hour deep dive into the genre. (Producers said they deliberately narrowed the scope to the 20th century.) And the topic came up this week during a webinar hosted by the Country Radio Seminar (CRS) in Nashville, which featured “Country Music” writer and producer Dayton Duncan, as well as country superstar Vince Gill, who made multiple appearances in the documentary.

At one point, Gill was asked about an episode in the film that addressed country music artists who tackled polarizing social issues in the 1960s. Why, moderator and CRS executive director RJ Curtis asked, do many modern country singers frequently refuse to discuss politics today?

After hailing Johnny Cash as one of country’s few truly outspoken artists, Gill added, “I stuck up for the Dixie Chicks 20 years ago when they buried them.”

By “they,” he clearly meant the industry response after Maines, during a March 2003 concert in London, famously said, “Just so you know, we’re on the good side with y’all. We do not want this war, this violence, and we’re ashamed that the president of the United States is from Texas.”

Maines’s quote went viral, and there was a furious response from the country music world. Even though the trio (also made up of Emily Robison and Martie Maguire) was one of the most successful acts in the genre’s history, country radio stopped playing their songs; fans destroyed their CDs; they got death threats.

As for Gill, he was indeed one of the few high-profile figures who came to their defense.

“There’s political leaders that said a lot worse things about George Bush than Natalie did. Nobody rips them for it, you know?” Gill said in April 2003 at the CMT Flameworthy Awards in Nashville, according to “I kind of feel like she’s been bashed enough.”

The next week, Gill clarified to the Tennessean that he held “the completely opposite view of Natalie Maines” because “the troops and the president don’t have a bigger supporter than me.” Still, he believed in freedom of speech. A month later at the Academy of Country Music Awards, the audience booed when the Dixie Chicks were mentioned. While onstage presenting the entertainer of the year prize, Gill admonished the crowd.

”Stop it, stop it,” he said, according to Entertainment Weekly. "You know who gets blessed when you forgive: you.”

On the CRS call, Gill said that Natalie’s father, steel guitar player Lloyd Maines, saw him a few years ago and told him, "I’ve been meaning to tell you this for many, many years, but you and Roseanne [Cash] were the only two people that stuck up for my kid. And as a father, I just wanted to thank you.”

(In 2003, Cash told Salon she was concerned about Maines: “What can we do to help this poor girl? I could not believe when I was in Nashville last week what they are doing to her: tractors running over the records, insisting that she go on TV to recant.”)

Gill is still struck by how the situation unfolded. “I found it pretty astounding that they kind of buried them for just making a probably not-so-polite comment,” he continued. “But all I said was, ‘Man, I hear people say a lot worse things about him every day up on Capitol Hill and nobody gets barbecued for that. Why are you going to take their career away from them?’ ”

Incidentally, getting “Dixie Chicked” in Nashville is still a real fear, and it’s why some artists fear speaking out about anything controversial. Gill himself doesn’t hold back: His new album, “Okie,” (which he calls “pretty edgy”) covers topics from teen pregnancy to sexual abuse.

“I’m not trying to make a statement and say ‘Believe what I believe,’ ” Gill said. “I just think if you can have a fair and decent and graceful conversation about any subject, nobody has to get completely unwound to the point of all that division.”

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