The Nine Muses

"In Greek mythology, the Muses (Greek Μοῦσαι, Mousai: perhaps from the Proto-Indo-European root *men- "think") are a sisterhood of goddesses or spirits, their number set at nine by Classical times, who embody the arts and inspire the creation process with their graces through remembered and improvised song and stage, writing, traditional music and dance. They were water nymphs, associated with the springs of Helicon and with Pieris, from which they are sometimes called the Pierides. The Olympian system set Apollo as their leader, Apollon Mousagetes. Not only are the Muses explicitly used in modern English to refer to an inspiration, as when one cites his/her own artistic muse, but they are also implicit in the words "amuse" or "musing upon".

they are the daughters of Zeus, king of the gods, and Mnemosyne, goddess of memory. For Alcman and Mimnermus, they were even more primordial, springing from Uranus and Gaia. Pausanias records a tradition of two generations of Muses; the first being daughters of Uranus and Gaia, the second of Zeus and Mnemosyne. Another, rarer genealogy is that they are daughters of Harmonia (the daughter of Aphrodite and Ares) which contradicts the myth in which they were dancing at the wedding of Harmonia and Cadmus."