Floor plan design single-family house with around 150 m²

Does it even have to be present all year round, can't it stand with the rest of the Oh-du-fröhliche decoration from Epiphany until the next use in the attic?

I suppose, since it is called a piano, that it has significantly more weight and volume than an electric piano or keyboard. In other words: you need at least two strong people to carry it. Once it is in the attic, no one will voluntarily carry it down again with the aim of increasing the Christmas contemplative atmosphere.

And I assume it is supposed to be used more than once a year.

I also wouldn't feel like laying an extension cord along the entire living room's outer wall to move the TV to the other side.

To significantly improve the living experience, is laying a few meters of self-adhesive cable duct supposed to be too much effort? Seriously?

Addition to the piano: Upright pianos (without grand pianos) are called Pianino according to Wikipedia and weigh between 175 and 300 kg. For repeatedly carrying them up and down, pianist hands are probably rather unsuitable.

Why isn't the ominous thing actually in the guest room? Apart from the fact that it's not exactly stylish, a guest room is simply predestined for such furniture

Why isn't the ominous thing actually in the guest room?

I assume that the pianist, with his virtuosic skills, also regularly wants to entertain his family and the guests present in the living/dining area. Possibly, the family also makes music together in some way.

If the family wished for dad to hide away with his tinkling box, they would probably let him know themselves somehow.

Katja, I think the problem is that the TV connections are on the other wall - so you are somewhat limited there. I also wouldn't feel like running an extension cord along the entire living room along the outer wall so that the TV can go to the other side.

Isn't TV available via Wi-Fi yet?