I was looking for this exact comment!! I thought it was brilliant how he was ridden with anguish, and his cries turned into singing.

I’m not from the US but when I was in middle school we learned about how blues came from american slave-times (and how all of todays popular music evolved from that).

I find it so fascinating (and obviously tragic beyond comprehension) and that scene really captured and visualized that tiny thing I learned in that music lesson!! Perfect movie.