"If a B&W photograph were a piece of music, what would it sound like?"
What indeed? It would depend on the photo.
I see this from the other direction.
Much music written through the ages is "program" music, as opposed to "absolute" music. "Program" music describes something. "Pictures at an Exhibition" is the most obvious example for this discussion, but the list is endless. Anybody's "Pastoral" Symphony, almost all ballets, opera scores, tone poems, etc.
There have even been projects like the two Disney Fantasia movies that made pictures from some "absolute" music, although the illustrations tended to be more abstract (Bach's Toccata and Fugue in d).
Ansel said something to the effect (can't recall the quote right now) of a good print being like a Bach fugue. I always thought that quote said more about Ansel than about photography, but that's just my opinion.
Do I see pictures when I listen to music. Yes, much of the time. Do I hear music when I look at pictures. Not very often. YMMV.
Having been trained as a musician with photography as a hobby, I have always been fascinated by the number of musician/photographers there are - including many on this site.
Cheers,
David