Christina Aguilera fluffed a line of the Star-Spangled banner as she belted out a version of the US national anthem to open Sunday's Super Bowl in Texas. The singer, 30, should have sung: "O'er the ramparts we watched, were so gallantly streaming?" but repeated an earlier line with a slight variation. She sang: "What so proudly we watched at the twilight's last gleaming." The anthem is one of the set piece events of the glittering Super Bowl pre-game ceremony. Aguilera's mistake immediately set social networks abuzz with chatter. Her representative could not immediately be reached for comment. Controversy The NFL final - which was this year contested by the Green Bay Packers and the Pittsburgh Steelers - is one of the most-watched programmes in US television. Last year it drew a record 106.5 million viewers. The half-time show of Super Bowl in 2004 created controversy when Justin Timberlake ripped a piece of Janet Jackson's top, resulting in a glimpse of her right breast. The pair said the incident was accidental, calling it a "wardrobe malfunction", but broadcaster CBS TV was fined $550,000 (£351,000) after hundreds of complaints from viewers. The fine was subsequently revoked in July 2008. Source: BBC