I wasn't quite sure whether to put this here or in General Pokémon, since this thread isn't about me sharing something I've created (I'm not sure I have a single ounce of musical talent), but about sharing awesome fan arrangements of Pokémon music.
Moisés Nieto does some amazing piano covers of Pokemon music. I really love his version of the Taupe Hollow theme from Pokemon Sleep: https://youtu.be/JxzuyEzVfc4
I also asked him if he could cover the Freezington theme from Pokémon Sword and Shield and he kindly obliged: https://www.youtube.com/watch?v=YSoIphuk0_o
Check out his channel for lots more chill Pokémon piano; I like to listen to his tracks while I write.
Another music channel I enjoy is PokéCello, who does some excellent cello (and electric cello!) covers. Give a listen to this lovely cover of the Kitakami theme: https://www.youtube.com/watch?v=jk9fLGV_-sE
As well as her cover of the East Province theme (probably my favorite track from Scarlet/Violet): https://www.youtube.com/watch?v=D1eDvgvPYdo
I'm amazed at what fans have been able to do with iconic Pokémon tunes, and I'd love to hear any that you're keen on!
