Don't even think about messing with Loleatta Holloway. One of the signature voices of disco, Ms. Holloway has been around since the early days and continues to be active today. In my humble opinion, the Walter Gibbons remix of her track Hit and Run is one of the most ferocious vocal performances in pop music.
This track from 1978 gives a good sense of what Loleatta's capable of. The breakdown towards the end is some qintessential Loleatta testifying. Norman Harris is the producer on this Gold Mind release from 1978. This version is the "Special Remix For Discos."