title: android -best way to communicate between activity and background service
body: <p>I'm trying to build a small MusicPlayer for learning purposes, and I'm stuck at a point on how to make communication between a background process and the activity.  I've haven't seen anyone else's code but in my(almost amateur design) the activity and the service must be updating each other every second since the activity's control should be reflected in the services controls(like if the service had a GUI in android's notification bar) and the music playing should update the Activity's seekbar etc.  </p>
  
  <p>What would be the best way to implement the service, so that it can run independent but in sync with the activity?  </p>