McKee's career began in the music Business in Detroit as a child Prodigy, where she started writing music/lyrics, singing, playing keyboards and performing at the age of seven. In 1968, McKee, then aged 14 recorded her first record entitled "Don't Worry About It"; which became an instant regional pop/R&B hit. McKee wrote the title song for the film Quadroon when she was fifteen in which her sister Katherine McKee starred.

Several years later, McKee was launched to stardom with her critically acclaimed performance in the hit 1976 musical drama film Sparkle. She has written and produced three solo LPs. Natural Love was produced for Spike Lee's Columbia "40 Acres and A Mule" label in 1992. Ed Hogan, reviewing for AllMusic, wrote: " 'Natural Love' shows that the singer/songwriter's muse knows no stylistic bounds. As with her earlier effort, McKee co-writes all of the songs while sharing production credits with Bryant McNeil, Gene Lake Jr., and labelmate Raymond Jones of State of Art." McKee scored the music for the well-received cable documentary on the Lower Manhattan African Burial Ground, as well as numerous infomercials. McKee has toured extensively throughout the world singing concert performances, including the JVC Jazz Festival at Carnegie Hall. McKee studied film directing at The New School in New York and apprenticed directing with filmmaker Spike Lee. McKee also studied singing with Dini Clark and ballet with Sarah Tayir, both in Los Angeles.

McKee won critical acclaim for her Broadway debut performance in the musical The First in 1981, co-starring in the role of Jackie Robinson's wife Rachel. She became the first African American to play the coveted role of Julie in the Houston Grand Opera's production of Show Boat in 1983 on Broadway, for which she received a Tony Award nomination for Actress in a Musical.. McKee's tragic portrayal of jazz legend Billie Holiday in the one-woman drama with music, Lady Day at Emerson's Bar and Grill won critical acclaim, standing ovations and a 1987 Drama Desk Award nomination (Outstanding Actress in a Musical). She reprised the role of 'Julie' on Broadway in the 1994 revival of the musical Show Boat directed by Hal Prince. McKee is currently developing plans to establish a performance arts center in the New York tri-state area. McKee performs her one-woman memoir with music on stages throughout the country. She is producing her first feature film Dream Street, which she wrote and will direct.

McKee was married to youth counselor Leo Compton from 1983 to 1990. In the mid-'90s, she was living in an Upper East Side brownstone with her companion, musician Bryant McNeil. The two had met while they were working together on McKee's Natural Love album. McKee teaches a master acting workshop at Centenary College of New Jersey, where she serves as an adjunct professor in the Theater Arts department.