thanks, bill; I now have all three(c) meanings attested to by loyal correspondents. as to the sense of it all, Occam's razor often doesn't suffice -- cf. southpaw.

Judi writes: If you WERE a "Barbershopper" you wouldn't consider this a "worthless
word"........ Sing bass for the women's group myself.

Tom offers: Being a frequent trumpet-playing member of community theater
orchestra pits, I can verify that definition b is actually used, usually
in the context of a conductor suggesting to a player that he or she
do some woodshedding, said suggestion usually being made
because he or she sucks.