Whistler

The Whistler is a device used by Booker DeWitt and Elizabeth near the end of the game BioShock Infinite. It is a pan flute device that is used for summoning Songbird by the sentry statues whenever they sense that somebody is in the same room as Elizabeth on Monument Island, or when she is with somebody away from Monument Island. Near the end of the game, Booker and Elizabeth gain use of the Whistler to summon Songbird in order to attack the Vox Populi zeppelins and to destroy the siphon tower. The notes played on the Whistler for summoning Songbird are C, A, G, E. After the siphon tower was destroyed, Booker dropped the Whistler from the bow of Zachary Comstock's flagship zeppelin.