Ad window popping up and music playing w/o me telling it to

[colamusiclover]

When I am using the app and get out of it, a black ad window will pop up and cover the screen of my phone. On top of that, when I brush it to the side or close it, my music will start playing and won't stop until I go to the app and close it or close out of the app completely. It has done this on multiple occasions and I don't know how to get it to stop. Help!