The horse fiddle is/was a name for a couple of different noise makers, one a
ratchet-type, used at shivarees (at least in Michigan, but would be curious
about it elsewhere).
The swinette is the subject of an old joke (Know what a swinette is? Take a
string, stretch it acrost a pig's ass and pluck it with your teeth and bow it
with your cock), but I wonder whether it might be related to the German
bumbass, which in its original version was a stick with a bladder, across
which a string is stretched. The modern bumbass is a noisemaker. There's a
guy in Wisconsin making "stump fiddles" commercially, which are his version of
the bumbass. I've also seen a commercially made bumbass from Cleveland. I
think they're popular with German- and Polish-Americans. I bought a nice old
bumbass in a junk store in Toledo once.
Paul Gifford