An assistant principal from Florida who blew away a crowd at the Lincoln Memorial earlier this month with her emotional rendition of "The Star Spangled Banner" did it on a dare.

The video of Star Swain's performance on June 16 has gone viral. At first, she told the camera, "I'm scared," then took a few breaths and started to sing. A crowd formed around her as the memorial fell silent.

When the song ended, her audience broke out in applause -- as Swain smiled from ear to ear.

“I was in that moment. I just closed my eyes and started singing," she told the Tallahassee Democrat. “One lady had tears in her eyes. I was kind of glad it was over. It was like a sigh of relief.”

Swain reportedly leads her church's music and arts department when she's not working at Jefferson County Middle/High School. She said she was vacationing in Washington, D.C. with friends and their families.

Benny Bolden, a fellow assistant principal, watched as church music minister Marcus Henderson held the camera. "What started out as a dare turned into all of this," Bolden told The Washington Post.

The video appeared on Swain's YouTube page hours later, but started going viral about a week later.

“We pray that great opportunities touch more lives in this way through music. I’m hoping that it will open up floodgates so we can do great things, for myself and others," Swain told the Democrat. “If I can do this with the gift that God gave me to touch more lives, then that is what I want to do.”