On Tuesday, a spokeswoman for the U.S. Marine Band told media that Beyonce had lip synced when she preformed "The Star Spangled Banner" during the ceremony.

　　However, the Marine Corps backed off that statement later of the day and released a statement, saying "there was no opportunity for Ms. Knowles-Carter to rehearse with the Marine Band before the Inauguration so it was determined that a live performance by the band was ill-advised for such a high-profile event.""Each piece of music scheduled for performance in the Inauguration is pre-recorded for use in case of freezing temperatures, equipment failure, or extenuating circumstances, " it added"Regarding Ms. Knowles-Carter's vocal performance, no one in the Marine Band is in a position to assess whether it was live or pre-recorded." Marine Corps spokesman Capt. Gregory Wolf noted.

　　Besides, a source very familiar with the situation said that Beyonce performed the National Anthem live, but she pre-recorded a track of the song to sing over.

　　This is a standard performing practice, the source added.

　　So far, the publicists of Beyonce have not responded to requests for comment.

　　According to the website MTV.com, there're a few artists who were proved to lip-sync at the major national events before: late U.S. singer Whitney Houston and Oscar-winner and former "American Idol" contestant Jennifer Hudson both lip-synced "The Star Spangled Banner" at the Super Bowl in 1991 and 2009.