How about these possible examples of "signifying" (cleverness contests, boasting contests):

1. The trading of insults among young men in the Inuit culture. It's quite old I believe. (Not songs of course)

2. Ballads in the Child collection like:
"The Twa Magicians" - Child 44 and "The Gardiner" Child 219 (courting one-upmanship)
or "The Devil's Nine Questions" (contests with Otherworld beings. The ballads in the Child collection from 1-4.

Does this help or are we moving further away? Cheers, Joy