The entire corpus of Vedic literature—the Samhitas, the Brahmanas, the Aranyakas, and the Upanishads—is considered Shruti (“What Is Heard”) and have been preserved orally. Several of these works, notably the three oldest Vedas, are recited with subtleties of intonation and rhythm that have been handed down orally from the early days of Vedic religion in India.