And it may be that some lyrical themes were so strong that they actually "inspired new frameworks". I would like to hear a bit more on this.

I was thinking along the lines of how new songs get created. Even when "from scratch," there is usually some kind of prior basis. Let's say that one way some new chanties came about was simply by a guy chanting something that came to mind, to an improvised melody -- similar to what Lighter was imagining recently on the "Advent" thread. What I am suggesting is that, in order to supply some kind of lyrics to this improvisation, one might draw upon a pre-set lyrical theme (eg Stormalong). In other words, in addition to lyrical themes being re-used and "grafted" upon pre-existing frameworks, they, being so "strong" and ever-present in the "language" of the genre, would probably also be used at that moment when a new framework was being created.

The framework (legisign, a la Peirce, ha ha!) cannot exist without a specific realization (sinsign!). So if it is a matter of chicken and egg...lyrics must come first, I think. They are the "wax" in the "lost wax" process! :)