Beating to Quarters is a drum pattern that was played to signal the crew. This involved clearing the main gun deck(s) by taking all extraneous gear and equipment and stowing it down in the hold. All the cannons were primed with gunpowder and loaded with the proper type of ammunition (roundshot, chainshot, barshot, canister shot/caseshot, or grapeshot). It was common during times of war for all ships to beat to quarters shortly before dawn, as enemies might be sighted during sunrise. Drum beats were replaced in the 20th Century by klaxons or bells.
General Quarters, or Beating to Quarters, is called at any time in which the ship or crew may face danger beyond that which is necessarily expected of them in a life at sea. Quarters are called during storms, battles, or random sightings in the fog. The general philosophy is that of preparedness. If a ship is to face the danger of the elements, and should happen upon an enemy, it is much better to be prepared.