How to listen to audio tracks while multitasking on iPhone 5s?

I want to know how I can play the audio tracks of music on my iPhone 5s which has the new ios7 in the background while I browse safari, open other apps on my phone and play games.

1. Open the iPhone and go to the App Store.
2. Press the "Search" option from the menu at the bottom of the screen. Enter the word "radio" into the resulting text box.
3. Browse the various radio applications that appear. TuneIn Radio and Pandora Radio are two well-known choices. You can also stream satellite radio to your iPhone, but this requires a monthly subscription with the satellite provider.
4. Enter your username and password to complete the transaction. The app will begin to download in the background. This should only take a few seconds.
5. Find the radio streaming application on the iPhone menu. Because it was just downloaded, it should appear as the last app on the menus.
6. Follow the app's instructions to start listening right away. Depending on the app, you may be asked to select from a preexisting station, a particular radio program, or to create your own custom radio station.
7. Enjoy live streaming radio on your iPhone either through the speaker or by connecting earphones.