In the Hindu tradition, sadness and compassion are the very origin of poetry.
Valmíki, a sage, is wandering in the forest when he sees “an inseparable pair of sweet-voiced krauñcha birds wandering about.” Just then a Nishada hunter, “filled with malice and intent on mischief,” fatally wounds the male of the pair. While the stricken bird writhes on the forest floor, his mate utters “a piteous cry” and the sage is filled with compassion. As he listens to the grieving bird, the sage says, “Since, Nishada, you killed one of this pair of krauñchas, distracted at the height of passion, you shall not live for very long.” As he meditates on his own words, Valmíki realizes their true nature: “Fixed in metrical quarters, each with a like number of syllables, and fit for the accompaniment of stringed and percussion instruments, the utterance that I produced in this access of shoka, grief, shall be called shloka, poetry, and nothing else.” Thus was the Ramáyana, and indeed, poetry itself, created.
--Eric Ormsby, "The jewel in the cobra's mouth" in The New Criterion, May 2005