American blues singer
According to Wikipedia,
Gertrude "Ma" Rainey was an American blues singer and influential early blues recording artist. Dubbed the "Mother of the Blues", she bridged earlier vaudeville and the authentic expression of southern blues, influencing a generation of blues singers. Rainey was known for her powerful vocal abilities, energetic disposition, majestic phrasing, and a "moaning" style of singing. Her qualities are present and most evident in her early recordings "Bo-Weevil Blues" and "Moonshine Blues".