Like many smartphones nowadays, your Samsung Galaxy S4 comes bundled with a headset for you to listen to music, watch videos without disturbing others, and even make phone calls. I personally only use it for music, whether it's Play Music, Pandora, or streaming from YouTube.
How To: Automate Battery-Saving Mode, Screen Rotation, & Other Custom Tasks on Your Samsung Galaxy S4
Automation is everywhere in our daily lives. Faucets and hand dryers that turn on for you when they detect your presence. Automated teller machines to handle your bank account. Timed sprinklers to water your lawn every morning. DVRs to record your favorite TV shows when you're not home.