Play button on earphones opens iTunes Pressing the play button on earphones opens up iTunes. Is there a way I can prevent this from happening without installing any third party programs? I would preferably want to control Spotify with my earphones.
Not if there's nothing currently playing. Play controls will try to resume the last thing you played that is still running and in memory. If the OS can't find anything to resume, it will default to iTunes. 

All media applications are equal; but, iTunes is more equal.