Songfacts®:

• Blood, Sweat & Tears lead singer David Clayton-Thomas wrote this song. Like "Spinning Wheel," he composed it in his native Canada before he joined the band. The song describes a woman of ill repute who will use men to get what she wants.
  
  Clayton-Thomas was inspired by the "bad girls" he saw in the funky bars he played when he was starting out.
• David Clayton-Thomas didn't want to use a real girl's name for this song, so it took him a long time to come up with a title. Inspiration struck after he had moved to New York. He was listening to a jazz station in Newark when a Horace Silver song called "Filthy McNasty" came on the radio. Silver described his song as being about a young man "of dubious character." When Clayton-Thomas heard this, he came up with a similar name for the character in his song: Lucretia Mac Evil.