It's hard to imagine country superstar Eric Church not having the jitters before his duet with Sullivan. In the lead up to performing the national anthem with her, he gushed to Variety that Sullivan "may be the best singer" he'd heard. He's not exaggerating. Because while Church may have started singing the national anthem (country twang delightfully intact), it was Sullivan's entrance that had us, and the rest of Twitter, holding our breath. Not everybody on social media was as positive though.