Hello Affair on Touhy Ave,
Just so you know, I was born at the end of 65', so as far as the Hula Hoop Song goes, I'm not sure...I will try to find out though.
As far as Black Day in July goes, perhaps he read about the them(riots), perhaps he was in Detroit at the time. Usually a writer has a trigger, an emotion or event which provokes her or him to write about something. The fact that the song is about the riots in Detroit, situates the song & its' listeners. My opinion...
Ingrid