Pavaniglia

The Pavaniglia is a genre, rather than a specific choreography. It could be considered as a form of lively, highly-ornamented pavana. The step-vocabulary is very like that of the passo e mezo, and broadly similar to that for galliard or canary. It's unlike these in that both man and woman dance continuously; usually the same passages, sometimes slightly different variations, but both dancing all the time.

There is a choreography in each of Caroso's books, two in Negri's book, and one in Santucci's. [Notes on all of these, and analysis of their similarities, will follow shortly.]

These look a lot like the improvisatory styles mentioned above - the galliard, and the passo e mezo - but I'm honestly not sure to what extent they were improvised. The fact that man and woman dance (and perform mutanze) simultaneously seems to argue against it, as does the high degree of consistency across several sources (for example, one of Caroso's and one of Negri's choreographies).

On the other hand, for highly-skilled dancers well-versed in form: maybe they could improvise mutanze.