By the standards of any musician, Rhiannon Giddens has a twisting and complex path. Trained as an operatic soprano at the prestigious Oberlin Conservatory, Giddens fell almost by chance into the study of American folk music. Alongside two like-minded musicians, she formed the Carolina Chocolate Drops, in which she plays banjo and sings. The group is focussed on reviving the nearly forgotten repertoire of black Southern string bands, but the audience for acoustic music remains largely white. Giddens tells David Remnick she was heartbroken that her largest black audience was at a prison concert. “The gatekeepers of black culture are not interested in what I’m doing,” she says. “This is a complaint I’ve heard from many, many people of color who do music that’s not considered black—hip-hop, R&B.” Her view of black music is more expansive: “There’s been black people singing opera and writing classical music forever.” As a solo artist, Giddens is moving increasingly far afield from African-American or American music; her new album, “There Is No Other,” recorded in Dublin in collaboration with the musician Francesco Turrisi, explores folk styles from the Middle East, Europe, and Brazil, as well as early America. She and Turrisi perform “Wayfaring Stranger,” the ancient ballad “Little Margaret,” and the tarantella “Pizzica di San Vito.”