Rushen is the elder of two daughters born to the late Allen Rushen and the former Ruth Harris. She demonstrated her musical potential at a young age; she was regarded as a child prodigy. In her teens, she attended south LA's Locke High and went on to earn a degree in music from the University of Southern California.
Rushen has many ground-breaking achievements. She became the first woman to serve as head composer/musical director for the Grammy Awards and the Emmy Awards, and the first woman to serve as musical director for the NAACP Image Awards' broadcast, an honor she held for twelve consecutive years. Additionally, Rushen has been the only woman to be a musical director/composer for the People's Choice Awards, HBO's Comic Relief and the only woman musical director/conductor/arranger for a late-night television talk show, The Midnight Hour.