O Ma Rainey, Sing yo' song;Now you's backWhah you belong, (27-30)
By saying that she's back where she belongs, our speaker let's us know that Ma Rainey is very much a part of the black community. In fact, she seems pretty pivotal in shaping the identity of that black community through music.
O Ma Rainey,Li'l an' low;Sing us 'bout de hard luckRoun' our do' (33-36)
It's request time at the concert. And the audience requests songs about the hardships they experience as black people in the South. By asking Ma Rainey to sing about this, the audience illustrates the deep connection between blues music, their racial identity, and the suffering they've endured as a result of it.