PlayerService: http://code.tutsplus.com/tutorials/create-a-music-player-on-android-song-playback--mobile-22778
PlayerNotificationManager: https://github.com/googlesamples/android-UniversalMusicPlayer/blob/master/mobile/src/main/java/com/example/android/uamp/MediaNotificationManager.java
SearchFragment (Submitting search call to the API with a delay): Steve Sharpe
ServiceUtils (whether a service is running or not): http://stackoverflow.com/a/5921190/1974562