Final answer:
Buddhist ritual music was most prominent during the Gupta period, from 320 CE to 550 CE, a period of significant cultural and religious development in India.
Step-by-step explanation:
Buddhist ritual music was well known during the Gupta period (320 CE - 550 CE), which was a time of significant cultural development in India. Along with the establishment of iconography in Hinduism and compilations of texts like the Kama Sutra, this period also saw a rich development in Indian music, including the ritual music associated with Buddhism. As Buddhism spread through trade and missionary work, its influence also reached early Southeast Asia between 300 and 600 CE, where it influenced daily life and culture, including music. The Gupta period is notable for being a time when many elements of what we consider traditional Indian culture were first formulated and consolidated.