GJim -

I've seen pictures of a number of fiddlers doing this, but I've only heard it done by a couple of unidentified players (on separate occasions) in the campground.

It generally, I think, requires either "disassembling" the bow to get sufficient slack, or in one case I believe the player just had a "spare" bow specially "haired extra long" specifically for this parlor trick.

The sound, as I recall dimly after many years, was akin to a hurdy-gurdy played badly or with a few broken keys, although if an act needs a gimmick it's a known one.

John