A guest at a Kentucky hotel was in for a surprise Wednesday when he discovered hundreds of high school choir students singing a rendition of the national anthem.

Garrett Mager, who was staying at the Hyatt Regency in Louisville, woke up hearing a lot of commotion in the lobby and decided to investigate, WSB reported.

Mager discovered that all the high school choir students participating in the Kentucky State Choir Finals were staying at the hotel, using their downtime to perform “The Star Spangled Banner.”

“Had a proud #American moment tonight,” Mager wrote in his Facebook post of the video. “They decided to sing the National Anthem together on every single floor. #Amazing.”

After Mager posted the video of the students’ performance, it went viral—generating 664,000 shares and more than 27 million views.

WKYT reported that more than 650 students spread throughout the hotel gave the performance, which is an annual tradition.