He played a few chords then he sang some more– (24)
African and African American music often have a reoccurring pattern called call-and-response. Here is an example of how a singer and an instrument act like two separate voices. The "voice" of the piano calls out a few notes or chords, and the singer responds by singing back to the piano in a similar melody. The two "voices" communicate back in forth in a melodic language.
"I ain't happy no mo' And I wish that I had died" (30)
Did you ever need to get something off your chest and it came out exaggerated? The singer is being dramatic here. He's hit rock bottom. By communicating this to his audience, or just saying this out loud, he takes a load off his shoulders and feels less weary than before.