As was previously reported by Master Sgt. Kristin DuBois of the U.S. Marine Band, Beyonce lip-synched the lyrics of the National Anthem over a pre-recorded track. However, DuBois is now backpedaling a bit on her claims.  She initially stated:

"All music is pre-recorded for the ceremony because there are so many eventualities and conditions that day. We performed, live, the band. But we received last-minute word that Beyonce was going to use the pre-recorded vocal track. Those were the instructions we were given. We don't know what the reason was."

She did add that it is common practice for artists to use pre-recorded tracks to either sing over, or lip-synch the entire song to, but she was baffled as to why Beyonce, who has such a powerful voice, would choose to do so at an event like this.

"We all know Beyonce can sing ... We don't know why she chose to use the pre-recorded track."

However, a Spokesperson for the Marine Corps. released a conflicting statement in somewhat of a defense of Beyonce, and further discredited Sgt. DuBois' previous statements.

"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."

This statement helps to credit Beyonce a little by providing the possibility for her fans that maybe she did sing live, just over a pre-recorded track. The rep did in fact confirm that a pre-recording of the music was used.

"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."

If this is the case and the band used a prerecorded track as well, then that would further contradict Sgt. DuBois' previous statements.

Beyonce and her reps still have yet to confirm whether or not she lip-synched.

Source: globalgrind.com