Besides being the singer of Ridinghood, Rhiannon is a Welsh mythological character. She is a moon goddess, muse to the poets.

Robert Graves calls her the White Goddess, but concedes that on account of her identity as Triple Muse she might also be the Red or the Black Goddess. White corresponds with Virgin or Life, Red with Woman or Sex, Black with Hag or Death.

In Welsh Mythology, the birds of Rhiannon are harbingers of death. Upon hearing their song on the battlefield, a warrior knew death was imminent.

The Triple Muse inspires the poets, but at a high price: they pay for her patronage with their lives. 

She appears in many forms and can take on multiple identities.