The play's opening scene WordNet 3.0 & Open English WordNet

The memorable opening bars of Beethoven's Fifth WordNet 3.0 & Open English WordNet

The opening act of the battle for Fort Sumter was the firing of a single 10-inch mortar round from Fort Johnson at 4:30 a.m. on April 12, 1861, by Lt. Henry S. Farley, who acted upon the command of Capt. George S. James, which round exploded over Fort Sumter as a signal to open the general bombardment from 43 guns and mortars at Fort Moultrie, Fort Johnson, the floating battery, and Cummings Point. Wiktionary

The opening theme of Beethoven's Fifth Symphony is, perhaps, the most recognizable in all of European art music. Wiktionary