The passage is the opening of a Bach chorale...
I was looking for a passage of the upper tetrachord in major. That seems relatively rare, and this was the best example I could find in the 371 Chorales before stopping about half way through them.
If I truncate it, I get...
...and to remove the parallel motion...
I'm I stretching too far (excuse the pun) to identify this as essentially a harmonization of the descending upper tetrachord?
The obvious "problem" is the retrogression
I don't mean to suggest the part I put in parenthesis is just a mere workaround for the retrogression. But, it's kind of hard to not clearly hear
I V at the opening paired with a
IV I closing within the space of only two bars as some kind of sequential idea. I'm thinking in terms of schemas, prototypes, and whether my truncated version might be a harmonic prototype for the descending upper tetrachord. Various modifications and insertions might be used to deal with the retrogression, but the basic four chords would possibly be the model.
Is this idea reasonable or contrived?