How do I play music via USB?

[AC Question]

When I plug my s7 edge into my car stereo via USB, I have one song that plays. I don't know where this song is or how I can add more music that will play on my stereo.

 

[Tim1954]

When you plug in your device, you should get a popup asking you what you want to do.. You have to allow the car stereo access to your files as it were... Pull down the quick settings menu and the usb thing should be there. If you're running Nougat, you can do so through the developers options...