Washington (CNN) - Pop star Beyoncé opted to use a "pre-recording" of her rendition of the National Anthem during inaugural ceremonies in Washington Monday, a spokeswoman for the U.S. Marine Band told CNN Tuesday.
U.S. Marine Band spokeswoman Kristen DuBois said early Tuesday that "we know why the decision was made," adding that the pop star "did not actually sing," but instead lip-synched her own voice.
Later in the day, however, the Marine Corps said in a statement that no one in their organization "is in a position to assess whether [Beyoncé's vocal performance] was live or pre-recorded."
The conflicting reports from the Marines have yet to be clarified by a statement from Beyoncé or her representatives, who have not responded to CNN's requests for comment.
Originally, DuBois said Beyoncé "pre-recorded" a version of the song the evening before Inauguration Day after rehearsing with the U.S. Marine Band.
In the later statement the Marine Corps said "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," the statement read.
DuBois said such pre-recordings are "not unusual," and that recording musical performances prior to inauguration ceremonies are a necessity in case something should go awry.
"We all know Beyoncé can sing and the Marine Band can play," DuBois said. "I've been with the band 14 years. It's not unusual."
"You can't have an inaugural without the National Anthem," she added.
American cellist Yo-Yo Ma was forced to use a pre-recording during President Obama's first Inaugural four years ago, due to frigid temperatures.
Many inauguration viewers may have also noticed Beyoncé pulled her ear piece out during her performance. But DuBois did not have an explanation as to why the pop star removed the ear piece.
The Times of London first reported the story.
A representative for Kelly Clarkson, who also performed at the ceremony, tells CNN Entertainment that Clarkson did indeed sing live. And a representative for James Taylor, another performer on Monday, confirms his vocals and acoustic guitar were live, as well.