This is a photo of a tuning fork. I had this idea of using an extremely shallow depth of field to defocus the prongs and make them look like they're vibrating -- a visual representation of sound, if you will, done without any postprocessing (other than making the photo black and white).
In case you're wondering: the tuning fork was in fact vibrating and sounding when I took the shot. Though it made no difference for the photo, that just felt like the right thing to do.
Incidentally, this was my entry for a friendly photo club contest. The theme was titled "Atonality", and it asked for photos suggesting a lack of center, independent parts, chromaticism, abstraction, and other elements often associated with atonal music. I didn't win, but I mention this because some of you may have noticed that shot is in fact a play on the title of that contest. You see, this is an A-440 tuning fork, so it makes a sound that's "A"-tonal. :D
<insert groans here>