Guessing that the "what kind of music with Stereomour/Cornwall" was aimed at me. Although still experimenting, I seem to be finding that to my ears, using the Cornwalls sounds best for music that is "complex" (this is hard to express) - Hendrix, Led Zep, Various classical forms and so on. The full range Madisound sounds best for vocals, acoustic guitar and the like. Of course, it depends upon mood (and maybe the phase of the moon). The Cornwalls do a good job on the latter, but the full rangers simply do it better (more clarity, better imaging).
As far as volume, moderate to a bit more.
Rich