I'm hearing a very mesmerising whistling thing in the background 👀 It feels nice to hear it go up and down.

Minus the slight dissonance that didn't quite sound like the Db major chord progression, I was thinking of melodic lines because I got compelled to, by looking at your description. The moments of dissonance made it a little hard for me, because I think I had a couple ideas. ^_^

Very nice tremolo :D