Edward Elgar's, 'Pomp and Circumstance'.

The title comes from a line in Shakespeare's Othello ("Pride, pomp and circumstance of glorious war") - in 1901.

But it was not originally intended for graduations. Elgar's March was used for the coronation of King Edward VII.

Since 1905, it has been used at virtually all high school and university graduations

in America.

The first time "Pomp and Circumstance" was played at a graduation ceremony, Elgar received a Honorary Doctor of Music from Yale University, June 28, 1905.

www.elgar.org

More Info: en.wikipedia.com