A band spokeswoman claimed tonight that players were notified at the last minute that Beyonce would use a pre-recorded voice track. The band played their instruments live.
All inaugural music is pre-recorded in case weather conditions or other circumstances interrupt the programme.
A representative for Beyonce did not immediately respond to requests for comment.
The use of a recording is typical in big events. In 2009, cellist Yo-Yo Ma was questioned about "hand-syncing" for Mr Obama's first inauguration. Ma said instruments were not functioning properly in the cold weather.