Thanks for the lead. It makes interesting reading. The song certainly has been duplicated, twisted and reshaped for a lot of circumstances but the discussion is more about the song rather than the meaning of Rosin The Beau.

I after I read through the file in "Rosin the Bow" (no wonder I couldn't find it before) I did go to the OED and found that the phrase Rosin-the-bow was used to refer to a violinist or a fiddler. The relationship of that to the vitality of the lyric is hinted at by the OED which says that "rosin" was a euphamism for drink, I guess "Some rosin for the fiddler" was like a fiddler's dram.

It's a small thing but with just this little bit of light on the old words of the song, they seem, to me anyway, to glow lot brighter.

Sourdough