Here is an excerpt from the Okehazama book.
From pages 62-63.
The next day Nobunaga was up at dawn and the first thing he did in the morning was to sing his favorite Noh play Atsumori, which runs, "Man's life is fifty years. In the Universe what is it but dream and illusion?" Is there any who is born and does not die?" In Japanese: "Ningen gojuunen, geten no uchi wo kurabureba, Yumemaboroshi no gotokunari, hitotabisho wo ete metsusenu mono no aru beki ka."
It was allegedly noted that Nobunaga held a fan in his hand. His lovely wife Nohime, played a hand drum. His voice was low and grave and she was shedding tears while playing the hand drum. The famous portrayal sounded romantic enough to make it authentic. Whether or not Nohime was there during her husband's finest hour, one act was true. He was preparing for war and for his death.
He was known to be found of songs, especially of Kowaka Atsumori and was skilled novice of several arts. There is a theory that Nobunaga sang the verse three times before heading off to war. The song and play itself was related to the Heike Monogatari. In the movie Kagemusha, Nobunaga sang Atsumori just before receiving news about Takeda Katsuyori's attack on Nagashino Castle. While singing Atsumori, it can be said he was arranging himself for a crucial confrontation with death.
Nobunaga was prepared for death and he was prepared for it spiritually. He was quoted in the Shinchoo-Koo ki saying, "Blow the conch horn! Bring the armor!" (Horakai wo fuke! Bugu wo Yokose!) It must have been a restless and wild atmosphere at Kiyosu Castle with people mobilizing for war at the last minute. He put on his armor, had breakfast (consisted of rice gruel), sounded the conch horn, and went on horseback with a few men.
Then Nobunaga got on his "Tsukinowa" and departed. According to Sugimoto Sonoko, the horse was chestnut colored and Nobunaga carried his "Honsho Masamune" sword with him to battle. The few men he departed with were Iwamuro Nagato, Hasegawa Hashisuke, Sawaki Touhachi (Maeda Toshiie's younger brother), Yamaguchi Hida, Gato Yasburo. The five men and their pages journeyed along with Nobunaga.
Nobunaga no tame! Tenka no tame!