The Hancock Concert Series will present “The Gift of Song: Voices of Black America,” a powerful and poignant celebration of the proud heritage of African American poets and composers in words and music, on Oct. 23 at 3 p.m. Included are lovely, familiar spirituals such as “Swing Low, Sweet Chariot,” and “Go Tell It on the Mountain,” contrasted with voices of protest in angular, jazzy works from the Civil Rights era. $15 suggested donation.