In many ways, history is marked as 'before' and 'after' Rosa Parks. She sat down in order that we all might stand up, and the walls of segregation came down.
The world goes up and the world goes down, the sunshine follows the rain; and yesterday's sneer and yesterday's frown can never come over again.
Hence my obstinate emphasis on stylistic continuity from work to work rather than specific sibling relationships between the individual work and other members of its stylistic 'family' in the world outside.