Hey, Murray, I can offer you some satisfaction on one of those... I got Ma Rainey singing "Black Bottom" on my House of Blues, Essential Women double CD. And she sings the whole song, not just the first line.
But, my friend, Black Bottom is a dance...as well as a double entendre...liner notes read:
""Ma Rainey's Black Bottom", a suggestive wordplay on a dance craze of the day, was one of her most populare domedic showstoppers, featureing "moneymaker" choreography that never failed to get the house rumbling."
If you want, I'll post the words.
Blessings,
Barbara