This could be a really cute space. I would definitely add a desk at one end like these pictures show (i would do it on end by closest to the door). Depending on your storage needs one end of the desk could be a storage unit with a simple top on it. It's hard to see the chair, but from what I see of it you could place it in the other corner, and then just pull up to the desk when you need to work at desk. Buy or diy a guitar holder so you can mount on wall and have it mounted close to the chair. Then get some fun prints to fill in the space closer to the desk. Get a desk lamp to help light the space. Hope this helps.

beep