Aguilera started out all right, but she had a problem with the ramparts -- specifically, the "O'er the ramparts we watched" line, which she left out altogether.
Aguilera tried to make up for it by combining two lines -- "What so proudly we watched," instead of "What so proudly we hailed" -- but let's just say that it was too late to reverse the error. Twitter blew up, and all Aguilera could do was to oversing every word from there on out, which she most certainly did.
It was a fitting tribute for a Super Bowl that has seen procedural errors all over the place, from the inability of the city of Dallas to deal with unusual weather to the last-minute news that 400 unlucky people would not get to sit in their paid-for seats.
In case you haven't seen it yet, here's the full performance:
On Monday, Aguilera explained her gaffe.
"I got so caught up in the moment of the song that I lost my place," she said. "I can only hope that everyone could feel my love for this country and that the true spirit of its anthem still came through."