Sillie & Millie Main Theme

For the main theme of Sillie & Millie, I really want to place a lot of importance onto the music, not just for marketing reasons but in terms of the theme of nostalgia, childhood, and innocence, I wish for the main theme to reflect those themes. I would like a simple melody that could be remixed into something more trans-formative, such as a sad tune, a happy tune, a catchy tune, or even a song with vocals. On top of that I want a tune that I, or a child/beginner, could play on a piano with one finger, because that makes it more comforting to the audience to take in, and could even inspire them.

I watched this clip of Angelo Badalementi talking about how he came up with Laura Palmer's theme from Twin Peaks for inspiration:

Here are the instructions I would like to give the person I hire to write the main theme:

"For this main theme, I would like this to be a simple tune that could be remixed into a more trans-formative version, such as a sad version, a happy version, or even a version with lyrics. It should be a very simple tune that a child, or a beginner piano player, could play on a piano with one finger. I want it to reflect the feeling of remembering a melody that you enjoyed hearing as a child, perhaps it could be a lullaby, a nursery rhyme, or a music box you enjoyed to play in repeat; regardless, it should reflect the feeling of hearing that type of melody again and feeling nostalgic for it. Here are a few examples of tunes that follow similar guidelines:

Eight Melodies - Earthbound (Mother 2)
http://starmen.net/mother2/music/131-%20Earthbound%20-%20Eight%20Melodies.mp3

Smiles and Tears - Earthbound (Mother 2)
http://starmen.net/mother2/music/153-%20Earthbound%20-%20Smiles%20and%20Tears.mp3

MOTHER 3 Love theme - Mother 3
http://starmen.net/mother3/music/Mother%203%20-%20045%20MOTHER%203%20Love%20Theme.ogg

Mom's Hometown - Mother 3
http://starmen.net/mother3/music/Mother%203%20-%20006%20Mom%27s%20Hometown.ogg

These are examples of songs that reflect similar themes of nostalgia, childhood, and innocence, as well as how they sound remixed with different meanings or with vocals.

Here are other examples of memorable themes that can be remixed:

Main Theme - Twin Peaks:
https://youtu.be/pXrjMaVoTy0

Falling - Twin Peaks:
https://youtu.be/_rZbsnB-xkM

Laura Palmer's theme - Twin Peaks:
https://youtu.be/khMlcTE7lw8

Audrey's Dance - Twin Peaks:
https://youtu.be/DF43b38k0Mw

Promise - Silent Hill 2:
https://youtu.be/6qalGezr76o

Promise (reprise) - Silent Hill 2:
https://youtu.be/8N_PXTGdlGw

I hope my instructions were clear and concise for you. If you have any questions, let me know."