In ancient Greek religion and mythology, the Muses (Ancient Greek: Μοῦσαι, romanized: Moûsai, Greek: Μούσες, romanized: Múses) are the inspirational goddesses of literature, science, and the arts. They were considered the source of the knowledge embodied in the poetry, lyric songs, and myths that were related orally for centuries in ancient Greek culture. Melete, Aoede, and Mneme are the original Boeotian Muses, and Calliope, Clio, Erato, Euterpe, Melpomene, Polyhymnia, Terpsichore, Thalia, and Urania are the nine Olympian Muses. In modern figurative usage, a Muse may be a source of artistic inspiration. Etymology
The word Muses (Ancient Greek: Μοῦσαι, romanized: Moûsai) perhaps came from the o-grade of the Proto-Indo-European root *men- (the basic meaning of which is put in mind in verb formations with transitive function and have in mind in those with intransitive function), or from root *men- (to tower, mountain) since all the most important cult-centres of the Muses were on mountains or hills. R. S. P. Beekes rejects the latter etymology and suggests that a Pre-Greek origin is also possible. Number and names
The earliest known records of the Muses come from Boeotia (Boeotian muses). Some ancient authorities regarded the Muses as of Thracian origin.
the causes and the crimes relate;
What goddess was provokd, and whence her hate; 
For what offence the Queen of Heavn began 
To persecute so brave, so just a man; [...] 

—Virgil (c. 29 - 19 BCE), in Book I of the Aeneid (John Dryden translation, 1697)
Besides Homer and Virgil, other famous works that included an invocation of the Muse are the first of the carmina by Catullus, Ovids Metamorphoses and Amores, Dantes Inferno (Canto II), Chaucers Troilus and Criseyde (Book II), Shakespeares Henry V (Act 1, Prologue), his 38th sonnet, and Miltons Paradise Lost (openings of Books 1 and 7). In cults and modern museums
When Pythagoras arrived at Croton, his first advice to the Crotoniates was to build a shrine to the Muses at the center of the city, to promote civic harmony and learning. Local cults of the Muses often became associated with springs or with fountains. The Muses themselves were sometimes called Aganippids because of their association with a fountain called Aganippe. Other fountains, Hippocrene and Pirene, were also important locations associated with the Muses. Some sources occasionally referred to the Muses as "Corycides" (or "Corycian nymphs") after a cave on Mount Parnassos, called the Corycian Cave. Pausanias referred to the Muses by the surnames "Ardalides" or "Ardaliotides", because of a sanctuary to them at Troezen said to have been built by the mythical Ardalus.