Mandy Harris Williams, left, and Alima Lee, right, founded Rave Reparations to help make dance clubs more black again. Frankie Knuckles, center, is an American DJ credited with popularizing house music. Illustration: Guardian Design Mandy Harris Williams, left, and Alima Lee, right, founded Rave Reparations to help make dance clubs more black again. Frankie Knuckles, center, is an American DJ cred