Though aging comedian Koo Davis is at the center of the novel, it's a kidnap thriller that breaks into multiple viewpoints, allowing Westlake to explore the attitudes of the time in the personas of Koo, his kidnappers, and the lawmen working to rescue him.
The first Hard Case Crime novel I read was a reissue of Westlake's 361. It, too, was different from everything else I'd read by him. I don't know that The Comedy Is Finished would have been published during Westlake's lifetime, or that readers would have appreciated it during his lifetime. I think it has more impact now, as a companion piece to his better known work.