Shirley Wahls has ultra heavy duty gospel credentials [the Ward Singers for one]. Basically, she's been singing in church her entire life. As far as I know, still is.
In the late sixties she made a handful of secular records, 6 or 7, on various labels. All of them are excellent, but for my money, this is the killer of the bunch. Doesn't matter which side gets played, they both blow me away every time.