upright piano

Well, not technically pianos, but I like this organ and this keyboard.

https://simverses.tumblr.com/post/670999825674911744/winterfest-day-19-sda-church-part-2

https://modthesims.info/d/551206/ts4-keyboard-piano.html

I also found these upright pianos. I haven't tested them but I like the way they look.

https://illogicalsims.tumblr.com/post/181915934339/upright-piano-base-game-something-different-to/amp

https://modthesims.info/d/549319/simple-upright-piano.html

https://www.thesimsresource.com/downloads/details/category/sims4-objects-furnishing-entertainment-hobbiesskills/title/upright-piano/id/1563841/

Nice pianos listed above.
Here's a couple more, if you want something fancy.

https://sims4updates.net/skills-hobbies/kurtzmann-piano-by-peterjames88-at-tsr/
https://sims4updates.net/wp-content/uploads/2020/12/762.jpg

or something unique:
https://sims4updates.net/skills-hobbies/medievalrenaissance-style-piano-by-esmeralda-at-mod-the-sims/
https://sims4updates.net/wp-content/uploads/2016/05/177.jpg

The new piano is nice but we could have used an upright piano instead, as we already have two big pianos.