Control music playback on another app

I have a finished app design for which I'd like to add controls for music. Implementation of the controls should be as generic as possible, to work with as many apps as possible. I'll be using Spotify as main reference. Controls wanted: Play/pause Next Previous Should previous-functionality be hard to obtain, that can be ok. To get this project you need to tell me what method you'll use to implement the controls (in private) and an estimate of how compatible that method is with music apps.