I already see a nice set of shelves. Do you have a book collection you need to house? There is no rule against it but with the shelves you already have, they might seem redundant and may not fit in well. You seem to have some nice pieces to work with, including the piano. Would love to help you get this room set and integrate more shelves if you need them. Please comment here and use the Attach Images button to add more pix of all 4 walls and furniture.

If there isn't one already, consider a more symmetrical design with another bookshelve units on the other side of the opening.

Love your rug.