Cat Power
Cat Power is the stage name for Chan Marshall, an American signer/songwriter from Georgia. She sings a bluesy, torchy kind of music that is hard to categorize. It's often minimalist with only guitar and piano.
Cat Power is also notorious for being a wack-job on stage, as she used to get severe stage fright, drink heavily to combat that fright, and then sometimes completely lose it while performing.
Recently, with the release of her album
The Greatest, her stage presence has gotten more assured and she actually seems like she enjoys performing now!
Some songs:
The Greatest
Lived in Bars
Maybe Not
Where is My Love