I heard the unblown flute
In the deep tree-shades
Of the Temple of Suma.
Basho visited Sumadera in the summer, and under the shades of the old pine-trees there, saw the flute that Atsumori (1169-1184) used to play in the castle before his death.
At the battle of Ichi-no-tani, when the Taira were defeated, Atsumori, then seventeen years old, was seized by Kumagai Naozane, d. 1208. In spite of the fact that Atsumori reminded him of his son Kojiro, he beheaded him, and sent the flute Atsumori carried to his father, Tsunemori. He spent the rest of his life at Kurodani praying for Atsumori's soul.
Heard melodies are sweet, but those unheard
Are sweeter; therefore, shakuhachi, play on;
Not to the sensual ear, but, more endeared,
Sound to the soul honkyoku of no tone.