Music by George Gershwin, lyrics by B.G. "Buddy" De Sylva & Arthur Francis(Ira Gershwin)from "George White's Scandals of 1922."
So old, so universally quoted that it has no known origin, only that it's Irish. The music is original to this site.
"Pomp & Circumstance March #1" (of 4) by Sir Edward ELGAR(1857-1934). Unofficially, this is the British National Anthem alongside "God Save The Queen." Also, a long-standing traditional tune for graduations. See Special Occasions/Graduation.