The Graces
The Graces were three happy Goddesses of Beauty. They were named:

Aglaia, Splendor
Euphrosyne, Mirth
Thalia, Good Cheer

They were the first ones to welcome Aphrodite when she was blown to shore by
the East Wind. The three of them rode in a chariot pulled by white geese. Their
name in Greek would have been the Charites. They were the daughters of Zeus
and Eurynome.
 
 

The Muses
The Muses were nine daughters of Zeus and Mnemosyne. They played and
sang all of the time and entertained the Gods and Goddesses on Mount Olympus.
They also inspired creativity in everyone. The Muses were:

Erato, the Muse of Lyrics
Euterpe, the Muse of Music
Thalia, the Muse of Comedy
Melpomene, the Muse of Tragedy
Terpsichore, the Muse of Dance
Urania, the Muse of Astronomy
Clio, the Muse of History
Polyhymnia, the Muse of Hymns
Calliope, the Muse of Epics

The last Muse, Calliope, had a child with the King of Thrace. The child's name was Orpheus. There's a great story about him.