second photo is a suggestion-- not sure if flow is bad and too cluttered.

Any thoughts?

Is there a tv in the built in?

are the two spaces on either side of the built ins openings to other rooms (so it's not a solid wall?)

Pianos are best not near windows if at all possible as for the rest we need more info and a to scale floor plan with no furniture showing all windows doorways where the doorways lead and FP and info as to how many seats you need too and a little off is not helpful

Here is an article on piano placement - https://www.total-piano-care.com/piano-room-placement.html.

Once you have the piano appropriately placed you can decide how to arrange the rest of the room.

What are your priorities? Is the room mainly for conversation or television viewing or listening to music? How many people need to be comfortably seated? Is it used at different times for different activities?

When I was growing up I played the organ every day after school and sometimes in the evening when my parents entertained friends or neighbors. The organ was in the living room. There was a TV in that room, but it was mainly only turned on when the boys watched football or on a Sunday night when the kids gathered to watch Wild Kingdom and The Wonderful World of Disney. The family room, next to the kitchen was where my mom watched TV while sewing, cooking or doing crafts, folding laundry . . .

The placement of the sofa in the family room was facing the TV. In the living room the seating was a conversation area - two sofas facing each other and 2 chairs facing the center of the two sofas. We laid on the floor to watch TV.

Many people like to make the fireplace the focus, but I don't see the logic in this placement. A century or more ago people gathered around the fireplace to read aloud and talk and stay warm. Not the typical family activities in a modern family.

Purpose of the room / activities should dictate the furniture placement.

I'll post a revised floor plan with as precise measurements as possible with labels. As for other questions, there is no television. This is a sitting/ conversation room with a piano. All of the openings lead to other rooms. We don't have a specific seat number in mind really, but at least 4 people would be nice.

I would say float a sofa/loveseat in the middle of the room with two small chairs facing the fireplace perpendicular to the sofa (so it leaves room for people to enter from the doorway behind, but creates a conversation area). then put the piano in the corner nook. leaving the windows clear of furniture.

Thank you, MelDesign. in your scenario, where is the sofa facing? I can't quite picture it. Thank you.

I might do 2 sets of swivel chairs and two ottomans.

Apologies, rudimentary image, but you get the idea. The sofa would need to be smaller or a loveseat as to not overwhelm the space. Same with the chairs. Then you could put a tall plant by the fireplace between it and the window (tall plant, tall tree) . Large painting or mirror on the wall across from the sofa.

No matter what layout you use, IMO the piano should be on the diagonal in the corner.