Room is way too bright.

You could do something as simple as hang some blankets in front of the windows when you listen — that’d probably help a lot and would be very cheap if not very elegant.  Curtains would obviously be a better but much pricier solution.  Another way to go would be to use some form of digital equalization/room correction that would likely very effectively address the issue.  Best of luck. 

EQ. 

verticle blinds can be had using softer fabric. Also, a much better solution, I did one room where a largest window behind the listener was fitted with plywood covered with glued on acoustic foam panels. Looked good and worked great and was easily removable if need be.

Try blinds from Hunter Douglas, totally worth it if you value an elegant and long term solution. My room has 3 windows (fortunately) and I went with Duette Cellular shades. 

https://www.hunterdouglas.com/window-treatments/sound-absorption

If you can't do anything else there's a variety of window film and installers.  Personally I dislike traditional blinds as I find they often don't cut enough light, or leave obnoxious holes of light through.

If you need to cut solar heat transfer you'll want metalized films, but if all you want is darker you can definitely do that with a variety of film with different grades of darkness.

Of course, there are more advanced slide up/slide down blinds as well.