I had no idea that ...Land of Hope and Glory was sung to the Pomp and Circumstance tune. Yes, Pomp and Circumstance, known to most of us Americans as "The Graduation March".

1911 performance sung by Clara Butt from www.firstworldwar.com

The tune is much better used for graduations. It was first used at a graduation in 1905 when Yale invited its composer, Elgar to accept an honorary doctorate of music. It quickly spread to become the ubiquitous choice it is today.