02-08-10: ViridianI'm right there with you in regards to Cassandra. She actually has a voice on the level of the greats when she's on, it's just undermined by the majority of crap music she chooses.
Cassandra Wilson seems to pay homage to the great vocalists of the past, not that she is in their class, while still having her own style and voice. Some of her material has been variable, but at her best, she has a lot to recommend her.
Her '83 disc "Blue Light 'Til Dawn" has some great music and phenomenal vocals on it. "New Moon Daughter" has a few, too. But, I don't have much patience for most of her other stuff - especially the New Agey crap. She seems to have trouble picking or sticking with a single coherent style.