(Charles Dharapak — Associated Press)

Dempsey, who was sworn in as chairman in September and serves as the chief military adviser to President Obama, was speaking at a think-tank seminar in Washington Friday morning when he was pressed by our colleague, Washington Post columnist David Ignatius, into demonstrating his reported ability to sing a rendition of the Irish holiday song, “Christmas in Killarney.”

The general, improbably, took the bait, and you can now hear it here.

Dempsey carried a reputation as a crooner before he moved to the Pentagon this year. In 2003, as commander of the Army’s First Armored Division, he sponsored a combat karaoke night at the Baghdad airport, where he took the mike to serenade the troops with Frank Sinatra’s “New York, New York.”

The next year, he was caught on video singing “Christmas in Killarney” with the First Armored Division’s band in Germany.

Mindful of that and other performances of his that still lurk on the Internet, Dempsey resisted slightly when Ignatius tried to goad him into singing at the end of the Friday’s event, sponsored by the Atlantic Council and attended by a very serious audience of military officers, diplomats and national security analysts.

At first, the general insisted that television cameras in the back of the room stop filming. “I’m not showing up on YouTube again,” he said with a smile.

A few camera operators obliged, but not all.

“I’m the chairman. Turn the cameras off or we’ll find a way to do it remotely,” he chided.

One cameraman, for C-SPAN, objected that he was filming the event live and couldn’t stop. Eventually, Dempsey relented.

The audience gave him a standing ovation.

Dempsey has a slightly unusual resume for a four-star general. He once taught English at West Point and holds a master’s degree in English from Duke University.

He’s scheduled to return to Duke on Jan. 12 to give a lecture on international security policy.

Here’s hoping (okay, a dare) that he serenades the campus audience with the school’s fight song, “Devil With a Blue Dress On.”

And, yes, Dempsey has been caught a few times on YouTube. A couple of his greatest hits here:

Dempsey sings “New York, New York” in 2010.

Dempsey sings “Christmas in Killarney” in Germany in 2004.