Audra McDonald (b. 1970) is an American singer and actress. She's appeared on TV on Private Practice and on stage in Broadway musicals such as Ragtime and Porgy and Bess, as well as the straight drama Raisin in the Sun.
McDonald provided the singing vocals for a chicken in the "Circus the Musical" episode of "Elmo the Musical," performing the song "Keep on Clucking." She will be making an appearance in person in a future episode. (YouTube)