Frederick William I had begun his military innovations in his "Kronprinz" regiment during the War of the Spanish Succession. His friend, Leopold I, Prince of Anhalt-Dessau, served as the royal drill sergeant for the Prussian Army. Leopold introduced the iron ramrod, increasing Prussian firepower, and the slow march, or goose-step. He also vastly increased the role of music in the Army, dedicating a large number of musician-troops, especially drummers and fifers, to use music for increasing morale in battle. The usefulness of music in battles was first recognized in the Thirty Years' War by the Brandenburger and Swedish armies. The new king trained and drilled the army relentlessly, focusing on their flintlock muskets' firing speed and formation maneuverability. The changes gave the army flexibility, precision, and a rate of fire that was mostly unequalled for that period. Through drilling and the iron ramrod, each soldier was expected to fire six times a minute, three times as fast as most armies.