Watch Zac Brown Band Sing the National Anthem at UFC Freedom 250 [Video]

The Zac Brown Band's Zac Brown led a powerful rendition of "The Star-Spangled Banner" to kick off the UFC Freedom 250 event on the White House South Lawn on Sunday evening (June 14.)

The night marked the first major sporting event to be held at the White House, and drew a crowd of about 4,300 invited guests and 85,000 spectators, per Yahoo Sports. UFC CEO Dana White and U.S. President Donald Trump were seated together in the crowd.

The event was tied to Freedom 250 celebrations revolving around America's upcoming 250th birthday. It also marked Flag Day (June 14) and Trump's 80th birthday (also June 14.)

Watch Zac Brown Band Sing the National Anthem at UFC Freedom 250

Brown ditched his traditional hat and boots for the performance in favor of a pinstripe suit and tie.

He began the anthem a capella, with his band mates and the United States Marine Band joining in on vocal harmonies.

Per USA Today, demonstration teams from the Navy and Air Force flew over the South Lawn during the final verse of ZBB's performance. Trump could be seen saluting, with a small smile, at the end of the anthem, as White cheered and clapped.

Why Was There Controversy Around Zac Brown Band's UFC Freedom 250 Performance?

Brown's participation in UFC Freedom 250 came as multiple artists (and even some states) were pulling out of Freedom 250 festivities. Martina McBride was among a large group of artists who canceled performances during the Great American State Fair, which was set to kick off later this month.

Read More: Martina McBride Pulls Out Of Great American State Fair, Lineup Crumbles

Per Fox News, a lawsuit was filed in an attempt to stop the UFC Freedom 250 event via emergency injunction, stating that organizers failed to adhere to federal permitting rules and environmental reviews. Documents associated with that lawsuit raise questions about whether the event is less about Independence Day celebrations and more about celebrating Trump's birthday.

Forbes also reports that some have raised questions about whether taxpayers will shoulder any of the costs for the event, which is projected to cost the UFC $60 million on production and lose about $30 million.

Last week, Brown defended his decision to remain on the Freedom 250 lineup during an appearance on The Pat McAfee Show.

He said he was "here for the troops," and "here to honor America."

"This is patriotism, not politics," Brown argued. "F--k all the division. I don't believe in that. I love this country. I love all the people that have sacrificed so that I can live my American dream...it doesn't have a place in politics for me."