The lights go down and thunderous applause shakes the seats of Iowa State’s Stephen’s Auditorium.

Country a cappella group Home Free took the stage on Wednesday night and serenaded the large crowd with their harmonious country stylings. 

“What’s up, Iowa?” prompted Austin Brown, the group’s lead tenor.

Home Free came into the national spotlight after winning NBC’s The Sing-Off in 2013 and was offered a recording contract with Sony.

Since winning The Sing-Off, the group has released three albums, all of which debuted on the Billboard charts.

As an a cappella group, Home Free features a lead tenor, Austin Brown, two harmony vocalists, Rob Lundquist and Chris Rupp, and a bass, Tim Foust. Adam Rupp, a skilled beat boxer, accompanies the vocalists.

Home Free’s shows are completely live. There are no recorded tracks or instruments, only the sound of their voices in the moment.

“This is a great way to kick off our spring tour,” Tim Foust said, before announcing the last song of the night: God Bless the U.S.A, bringing the audience to their feet.

…Iowa, y’all are too good to us! Thank you for an amazing first show @StephensAud tonight in Ames. We’ll be back real soon!

— Home Free (@HomeFreeGuys) February 11, 2016

As the last chord of the song resonates through the auditorium, the lights go down and the group bows before leaving the stage as the audience applauds.

But the performance is not over.

Persuaded by the chanting crowd, Home Free reappears and performs Ring of Fire as a parting gift to the enthusiastic audience.

“Thank you, Ames,” Austin Brown said as the lights go down for the final time.

THANK YOU AMES!!! #WhatAGreatWayToStartOffTheTour #ThankYou #DontItFeelGood pic.twitter.com/vVwYb81TZ6

— Home Free (@HomeFreeGuys) February 11, 2016