Thornton's performances were characterized by her deep, powerful voice and strong sense of self. She was given her nickname, "Big Mama," by Frank Schiffman, the manager of Harlem's Apollo Theater, because of her strong voice, size, and personality. Thornton stated that she was louder than any microphone and did not want a microphone to ever be as loud as she was. Alice Echols, the author of a biography of Janis Joplin, said that Thornton could sing in a "pretty voice" but did not want to. Thornton said, "My singing comes from my experience... My own experience. I never had no one teach me nothin’. I never went to school for music or nothin’. I taught myself to sing and to blow harmonica and even to play drums by watchin' other people! I can't read music, but I know what I'm singing! I don't sing like nobody but myself."