The voice that will announce the arrival of dignitaries at the inaugural ceremony tomorrow--members of Congress, present and former high-ranking government officials and, of course, the President-elect, will be that of a U.S. Navy Musician.
MU1 Courtney Williams is the concert narrator for the United States Navy Band.
According to this story in the Washington Post, Williams is experienced at announcing arrivals at military ceremonies. I think he'll find a presidential inauguration is slightly different from the typical change of command:
People, for once, will be paying attention.