You can control music playback, even if the screen is locked. Simply press the Home button once to reveal the controls. These will only appear if you’re already playing audio from the Music app or elsewhere.
From here you can pause, skip, increase volume, and see more details about the song.
Lock screen suggestions
As soon as you plug headphones into the headphone jack, the iPhone will take a guess at what you want to listen to and present the play controls for the suggested audio app. With some content, you can hit the play button right from the Lock Screen to get started. Otherwise simply swipe up from the app icon in the bottom left to launch straight into the suggested app for more direct control of what to play.
The app suggestions are based on frequency of use, current time and location. For example, your iPhone will learn if you always use the Music app at the gym or listen to the Podcasts app on your morning commute, and make recommendations accordingly.