I don't know what kind of music should I use for this

I’m currently working on a Sudoku game.
I’m deciding to add music into it.
But I don’t know what kind of music should I use for it.
Here is the picture:

I think the music should be smooth/quiet/lonely
I can’t find any music like that.
How do you guys think?

Or I make music by my own, Is there any free music editor?

Either classical music or elevator music. Since your shooting for smooth and calm, I think those could work.

If I were you I wouldnt have any music but instead some calm nature sounds. Like in the woods with some bird chirpering.

Music for me would’ve ruined the whole experience in my opinion.

You must use peaceful songs:

Elevator musics
Facilities musics
Natural musics

Those are my ideas.

This maybe? It’s beautiful, calm, non-copyrighted and it fits in with the image you posted.

Just listen to a minute of this and you’ll love it.

if you’ve ever played geomerty dash, the music for the practice play is something you should go for. You need the music have a “practice”, or “puzzle” message that give the player concentration.

Something along the lines of this (skip to around 0:25 for what I mean).
Don’t use it as it’s not yours! But you get the idea!