Clark became known to Northern soul fans for hit songs such as 1965's "Do Right Baby Do Right" (by Berry Gordy) and 1966's "Love's Gone Bad" (Holland-Dozier-Holland).

She later co-wrote the screenplay for the 1972 motion picture Lady Sings the Blues starring Diana Ross,[1] which earned Clark an Academy Award nomination.

[1] The album featured twelve songs including a rare Motown ballad called "If You Should Walk Away" (Berry Gordy, Jr.) which was slated for release as a single, but never was.

Clark became famous in England as the "white negress"[3] (a nickname meant as a compliment), because the six-foot platinum blonde, blue-eyed soul singer toured with fellow Motown artists, who were predominantly black.

Clark co-wrote the screenplay for the 1972 motion picture Lady Sings the Blues[1] starring Diana Ross, which earned her an Academy Award nomination.