Could you post a few more photos of the other walls and adjoining rooms, that would help visualize the spaces. I assume the piano is not yours? Your wall reminds me of Southwest rooms with adobe designs and they have great ideas for using spaces like these. Here are a couple to inspire you to be creative with designing the spaces. If you need a TV on this wall, I would do everything I can to disguise it. Or at least keep it to a size that does not overwhelm the space.

Of course, this is very high end look, but notice how they used paint color and stone and lighting to really enhance the look of this unusual wall. You could steal some ideas from this. I believe the TV is hidden behind those panel doors.