gchucky,
Beautiful room. However, I need a bit of clarification on what you mean by "primarily for music"?
A) If you mean for critical listening from a very capable/expensive stereo or more system, I would strongly advise finding a less challenging room (less reflective floors, fewer/smaller windows, less odd angles/openings, etc.)
B) If you mean suitable for background music, parties, casual listening, etc. then I would advise exploring if you can access/mount a few (2-4) in-wall, dual-voice coil, speakers along the high wall shown on the left of the first/top photo (i.e. photo with fireplace and the wall where the visible hvac outlets are), as well as planning on a sub to fill in the bottom octave a bit. The in-wall speakers will also need to have aim-able tweeters.
If option B interests you, respond and I/others will provide more details. I have a room not quite as difficult as yours and was able to implement a 4.1 system which produced decent results.
Cheers,
XEagleDriver