They all sound great when they're working. It's when they hesitate or stop half way that they cease being musical.
Here, here. But some do have a more distinct sound than others. Weighing in, I would give a nod to either the Hasselblad 553EL/X or an F2 w/MD2 chewing through film whilst set on "M3." Or, for a quieter touch...an M series.
The sound that my cell phone makes when I'm 'sneaking' a Q&D of grandson sounds somewhere between the copal and the compur but not as quiet as my compur electronic shutter. I was not aware that either copal or compur made mechanical shutters small enough to fit in behind that small lens on the back.
There are holes in the sky where the rain gets in,
But they're ever so small that's why rain is thin.