The Muses are the nine daughters of Zeus and Mnemosyne. The are listed by name but the specific attributes of each goddess were added later by poets, which were:

Kleio, history
Euterpe, flute playing
Thaleia, comedy
Melpomene, tragedy
Terpsichore, dance
Erato, love poems
Polymnia, sacred music
Ourania, astrology
Kalliope, epic poetry

Mere mortals who are blessed by the Muses, can use the beauty of song and grace to heal the sick and comfort the heartbroken.

It was said in one story that a singer and a poet named Thamyris challenged the Muses and mocked them and destroyed their skills. Because of his ignorance, he lost his memory and could no longer remember his songs or his poems. While the Muses can give the gift of talent, they can also revoke their blessings.