There are multiple artists with this name:

1) Ruth Barrett (born in Los Angeles in 1954) is a Dianic Wiccan High Priestess in the direct lineage of Z Budapest.

She was a member of the Moon Birch Grove coven before becoming the spiritual director of the Circle of Aradia in Los Angeles, from its founding in 1985 until 2000. She then moved to Wisconsin and co-founded The Temple of Diana with Falcon River.

Ruth is a singer and songwriter, who plays the fretted dulcimer.

http://www.dancingtreemusic.com/

2) Ruth Barrett (born 1976) is a British film score composer. Her film score credits include Harry Brown, Twenty8k, and City of Tiny Lights. Her television score credits include Bodyguard, The Durrells, Collateral, Legacy, and Victoria. Read more on Last.fm. User-contributed text is available under the Creative Commons By-SA License; additional terms may apply.