Dee Dee Warwick. Delia Mae Warwick. Dionne's younger sister, Whitney's cousin, and the one who got the voice with the dirt under its fingernails. Dionne had the pop crossover. Dee Dee had the grit. She Didn't Know (She Kept on Talking) is Northern soul gold -- a record that built slowly and exploded into a chorus that could fill a warehouse. Two Grammy nominations. Sang backup on countless sessions. Died at 66, and the obituaries still called her 'Dionne Warwick's sister.' The records tell a different story.