I finally finished this, in the nick of time to enter it into a show (in New York City!) that is asking for work that is totally imaginary, that is, that wasn't made using references.
I'm not holding my breath about getting in. Shows like this are a longshot at best, but it is unusual to find anyone that makes the distinction between work that is copied from photos and work that is purely from the artist's brain, so I had to try. The title I finally settled on is Prelude and Fugue. I hope Claire Corriveau will approve.