Lu Chuan’s Nanking & Japanese Culture

(From wiki)

Uses of the taiko (drums) in warfare

In feudal Japan, taiko were often used to motivate troops, to help set a marching pace, and to call out orders or announcements. Approaching or entering a battle, the taiko yaku (drummer) was responsible for setting the marching pace, usually with six paces per beat of the drum (beat-2-3-4-5-6, beat-2-3-4-5-6).

According to one of the historical chronicles (the Gunji Yoshu), nine sets of five beats would summon an ally to battle, while nine sets of three beats, sped up three or four times is the call to advance and pursue an enemy.

————–

Others interesting facts about taiko:
———————————
Religion:
The rumbling power of the taiko has also been long been associated with the gods, and has been appropriated by the religions of Japan. According to Daihachi Oguchi of Osuwa-daiko, about four thousand years ago, in the Jomon period , taiko was used for to signal various activities in the village. Simple taiko beats would be used to signal that the hunters were setting out, or to signal that a storm was coming and that the women needed to bring in the meat and fruits they had drying. While there is no direct physical evidence to support this claim, Megumi Ochi, curator of the Taiko Kan Museum, believes this to be true since other cultures exhibit the same behavior. Because these signals were so important to the flow of daily life, the people were very thankful of the taiko, and began to believe that the taiko was inhabited by a god.
Taiko has continued to find a place in religious ceremonies, both Buddhist and Shinto, and it is extremely common to find taiko in both temples and shrines. In fact, the Nichiren sect is credited with created the uchiwa style taiko, who used it as an aid in chanting. Some Buddhist sects use taiko to represent the voice of Buddhah, and Bon dancing in summer is centered around Buddhist rites. It was used in village Shinto rites to offer up prayers to the Gods.
—————————–
War:
Reputedly, one of the first uses of taiko was as a battlefield instrument; used to intimidate and scare the enemy – a use to which drums have been put in many cultures. Taiko were definitely used in battle to issue commands and coordinate movements by the 1500′s; the taiko being the only instrument that could be heard across the entire battlefield. According to picture scrolls and painted screens of the time, one soldier would carry the taiko lashed to a backpack-like frame, while two other soldiers would beat the taiko, on each side. Both nagado and okedo style taiko were used in this capacity. A war taiko used by Shingen Takeda, a famous warlord of that era, still exists and is preserved by Osuwa-daiko. It is remarkable for the three large holes cut in the side of the nagado style taiko. This served to increase the volume of the drum, useful in battle.
————————————
from http://www.taiko.com/taiko_resource/history.html#research