History of the Peloponnesian War

After this the conflict commenced: the Argives and their allies advancing with haste and impetuosity; the Lacedaemonians slowly, and to the music of many flute-players, placed amongst them according to custom, not with a religious object, but that they might advance evenly, stepping in time, and so that their line might not be broken, a thing which large armies are apt to do in their approaches to an enemy.