After 30 years and 18 albums, the African-American acappella troupe Sweet Honey in the Rock doesn’t require introduction. Although many women have come and gone, the core remains stable: all current members have been involved for years. The Women Gather is produced by singer/songwriter Toshi Reagon (the founder’s daughter), with assistance from Bernice Johnson Reagon herself. Inventive arrangements make ample use of unusual vocal effects, some emulating throat singers. Such communal techniques, as well as judicious use of percussion, add a variety of rhythmic effects. The group sings mostly original songs concerning black history and racism (“Ballad Of Harry T. Moore,” based on a poem by Langston Hughes), victims caught in crossfire (“The Voice Of The Innocent”), and the resilience of human spirit (“Let Us Rise In Love”); a few titles—such as “Give the People their Right to Vote!” and “Ballad of the Sit-Ins”—tackle poignantly activist history.