Fiddler - carte-de-visite, Janus Museum Collection.
I bet this unknown fiddler was playing a tune as the photographer prepared his plate and focused the camera - maybe the tune was Bonaparte’s Retreat. Then the photographer looks up and says “Just hold it for a sec…” The fiddler pauses with the bow in mid-stroke - the photographer pulls off the lens cap, counts out his exposure, and replaces the cap. “That’s about it” he says, and the fiddler picks up the tune, and he plays it to the end.
What we have here is a true photograph of a song interrupted, taken about a hundred and thirty years ago.