A hint as to the actual origins of the version Beyoncé sang came from her own hand: On January 20, the day before the ceremony, Beyoncé posted pictures to her Instagram account that appeared to show her in a recording studio. In one, she holds a copy of the sheet music to “The Star Spangled Banner” in front of a microphone attached to a recording device, and in another she sits in front of recording equipment while members of the Marine Corps Band stand clutching sheet music behind her.
Miming along to a pre-recorded track isn’t unheard of at inaugural ceremonies. At President Obama’s 2009 inauguration, cold weather and wind meant that a live performance by cellist Yo-Yo Ma and violinist Itzhak Perlman had to be nixed in favor of a recording. But there are no previously known cases of a singer lip-syncing the national anthem during an inaugural performance.
Source: Washingtonian