Music Sets the Mood

I wish I could identify the instrument that is common among all the songs that I'm about to mention. It's probably some kind of synthesized instrument anyhow. But whenever I hear it in a song, it takes me back...
Ok, here are the songs:
Ours - Taylor Swift
John Mayer - No Such Thing
The Police - Every Little Thing She Does is Magic

Is it an instrument in the song? Is it the speed and tempo? I don't know. It does just take me back. Back to being five years old, and in the back seat of my mom's car. Whenever she drove us, I felt safe enough to fall asleep. We would be driving in the cold of winter, but the sky would be blue. Everything would seem a lot brighter, because the sun would be bouncing off the snow. It was cold outside, but in the back seat of the car, I was nice and warm. The sun would be shining in.

I would look down at my hands, they, of course being tinier than they are now, but seeming very normal sized to me. I would lay my long fingers flat, and look at the dimples my knuckles made. I just remember finding that incredibly fascinating. Then I would close my eyes, and fall into differing levels of sleep. The first one being with my eyes closed, but I could still feel the sun shining through my eyelids. I would pretend to be asleep, and just listen to the adults talk. I just wanted to listen to everything they had to say. Then their conversations became more abstract to my little five year old mind. I would drift in and out of sleep. I was mostly able to sleep, until the car made an abrupt turn or sudden stop. That might jolt me out. Finally, I was actually asleep, and so tuckered out that I would wake up in my own bed, not really knowing the difference.

You can never go back to being a kid. But so many things, like the music, set you in that mood, that takes you back to being five and daydreaming in that car.