For the exquisite vocalists of the a cappella group Sweet Honey in the Rock, being a musician is a humanitarian calling. Five voices strong (plus sign language interpreter), the internationally embraced choir of African-American women celebrates the transcendent harmonies and driving rhythms of the African Diaspora—the blues, spirituals, gospel, hip-hop, reggae, jazz—and puts these sounds at the service of a message of social justice, tolerance, and equality. High-profile performances have included a concert at the White House during President Obama's first month in office, and a collaboration with Alvin Ailey American Dance Theater.