Those categories seem great. I remember in Morrowind, there was this battle song I loved, but since it was completely random, I often got it fighting cliffracers and nix hounds, when I should have gotten it fighting mages or daedra, or other strong baddies.
Music is so important and does so much...sure, it'd be more trouble for Jeremy Soule, but if Beth already thought of having diverse music, well...not much he can do about it lol Its not like he works for free (both in terms of monetary game, and the prestige of continually creating awesome soundtracks).
It'd be really cool if each city had its own music, and Dwemer ruins had different music to barrows, caves,mines, ect.