The Three Graces, and The Nine Muses
The Three Graces.
Daughters of Zeus and ?? (variable and controversial claims about mother)
Companions of Aphrodite, Goddess of Love
Taken together, represent Charm, Beauty and Human Creativity.
They are intertwined, touching, in nearly every painting and sculpture.
Various names and attributes, and in some traditions, 5 or more graces.. Charites in Latin..
In Antonio Canova’s famous sculpture, they are, left to right, Mirth, Grace and Beauty (my names):

The Three Graces were also, in my mythology, light-fingered governesses of The Nine Muses, also manifestations of GRACE, who were daughters of, perhaps, Uranus and Gaia, as I think, or Zeus and Mnemsyne. Originally nymphs at sacred wells, they were also goddesses of knowledge, remembering all that had come to pass, and were often accompanied by Apollo.
The power of the Muses (collectively, as they are best seen) is “to bring before the mind of the mortal poet the events he has to relate; conferring on him the gift of song; and giving gracefulness to what he utters.”
The nine cluster nicely, three by three, under the Graces. (Their names supplied by Hesiod).
Euphrosyne. Mirth, Joyfulness, Song
Polymnia, Religious Hymns
Terpsichore, Choral Song and Dance
Euterpe, Lyric Poetry
Aglaia. Elegance, Brightness, Splendor (Adornment, Glory)
Urania, Astronomy
Clio, History
Calliope, Epic Poetry
Thalia. Youth, Beauty, Bloom
Thalia, Comedy
Melpomene, Tragedy
Erato, Erotic Poetry