I made some changes to the Sub-Genres area, but I think it still needs some work. Perhaps someone could break out the aural information and expand upon it separately. My edits seem to have changed the focus to a discussion of periods within the development of Cajun music, which seems to be separate.
Discussing Cajun music by period is tricky. Some of the sub-genres exist side by side. For instance, Dancehall continues today alongside Folk Cajun and Zyde-Cajun! I am not sure the term Zyde-Cajun is accurate either. It applies to Wayne Toups and bands that have followed his lead, but groups like the Pine Leaf Boys, Beausoleil, and Steve Riley also use some Zydeco elements. I would prefer if the were called Contemporary Cajun Music and play up its use of rock and Zydeco for a younger audience of dancers. The godfathers were Zachary Richard and BeauSoleil, then Wayne Toups. Steve Riley marked a return to a more traditional dancehall sound, but evolving into something different with swamp pop and Zydeco elements, etc. Also, Folk Cajun is more popular in the Lafayette area as shown by the types of bands in the venues it offers, while Zyde-Cajun is more popular in the Lake Charles and more small town areas.
The Cajun String band entry has problems. It sort of mixes the string band era of the 1930s and 40s with later developments in the 50s and 60s such as Jimmy C. Newman and Doug Kershaw. Many people of a certain generation were first exposed to Cajun music through Doug Kershaw and look at Cajun music from that perspective. Perhaps the Cajun String band sub-genre of the 30s and 40s, which included Hackberry Ramblers, Leo Soileau, Happy Fats, Harry Choates, etc. could be separated out, and add an area called Cajun Country that would include Jimmy C. Newman, Doug Kershaw, Vin Bruce, and others. This could include country music with "Cajun" themes, such as the link to different versions of Jolie Blonde is suggesting. I don't think that link gives a true idea of Cajun music at all, just an Americanized one, but if it is to be kept, it could be kept separate in a Cajun-Country area.
Folk Cajun is a sort of fuzzy category too. If it is meant to correspond somehow with the appearance of Cajun musicians at folk festivals from the 1960s to the present, that's fine, but I am not sure the aural description is accurate. Especially the remarks about the fiddle. To my mind, I just distinguish it from Dancehall by its lack of steel guitar, but then again, Lost Bayou Ramblers are using lap steel! The major difference may be the audience. Folk Cajun appears to be the kind of music heard in Lafayette in several venues, mostly restaurant-dance halls, while Dance Hall is more like Walter Mouton at La Poussiere, Ed Gary at the Jennings VFW hall, and that sort of thing.
La Brise du Bayou, perhaps, could go with a category called New Trends Among Cajun Musicians. This would help make it clear that it is created by Cajun people, hence Cajun music, but more like contemporary rap music sung in Cajun French, NOT the fiddle and accordion thing. I think we need to maintain that Cajun music is sung in French. Bluegrass music played in Japan and sung in Japanese is still bluegrass music, but it is different with Cajun music, which is the music of an ethnic group. If it is sung in English, like Alligator Man or Louisiana Man, or Diggy Diggy Lo, we could have it in the Cajun Country area with Jimmy C. Newman, Moon Mullican, Doug Kershaw, etc.
We could add a genre called Cajun music beyond Louisiana and Texas, but really most of those bands play either the Folk Cajun or a hybrid of Cajun and Zydeco.