Complex sentence: A warm-weather uniform substitutes a white blouse, while the cover is a red peaked hat that represents the red coats U.S. Army musicians historically wore on the field of battle to distinguish them from non-musicians.
Split into simpler sentences: A warm-weather uniform substitutes a white blouse. Cover is a red peaked hat supposed to represent the red coats U.S. Army musicians historically wore on the field of battle to distinguish them from non-musicians.