Casel has contributed a number of original musical compositions and contemporary arrangements of traditional African songs to Sweet Honey in the Rocks repertoire. Her compositions are also included in a children's textbook, World of Music, and The Box, a pilot TV show from Robert De Niro's Tribeca Production Company.
Casel appeared in the 1998 film Beloved starring Oprah Winfrey and Danny Glover. She was also a guest artist in the Smithsonian Institution production of Duke Ellington's Great Ladies of Song.
Casel is a co-director of First World Productions, a cultural and educational performance arts organization.