The Imperial March

The Imperial March was the national anthem of the Galactic Empire. It's performed by Imperial Military bands across the Empire, at state ceremonies, military parades, and other events, specifically during and after battles with the New Republic.

During the Second Battle of Cochran, Imperial troops played the March utilizing Lambda-class shuttles equipped with external speaker systems to demoralize Republic and Griffon troops during the battle, and raise Imperial morale.

Behind the Scenes
Yes, the Imperial March utilized ICly is the same March as in the movies.