1. In Hinduism, sometimes a single god, who is the guardian of soma. More often they are in the plural, described by the Atharva Veda as half-human, half-bird, and hairy. In later texts (e.g. Mahābhārata), they have become the musicians of the gods (with the apsarasas, the dancers) who also threaten to seduce ascetics when they rival the gods.
2. In Buddhism, (Pāli, gandhabba) they continue as heavenly musicians, but they also have a role in sustaining the karmically governed accumulation of consequence from a previous life, through death, into a new appearance. They thus covered, mythologically, the ‘gap’ between death and new birth.
"Gandharva." The Concise Oxford Dictionary of World Religions. . Encyclopedia.com. (September 24, 2018). http://www.encyclopedia.com/religion/dictionaries-thesauruses-pictures-and-press-releases/gandharva
"Gandharva." The Concise Oxford Dictionary of World Religions. . Retrieved September 24, 2018 from Encyclopedia.com: http://www.encyclopedia.com/religion/dictionaries-thesauruses-pictures-and-press-releases/gandharva