How to Use Playlists on Your iPhone
You can use playlists on your iPhone just as you can on an iPod. To use playlists on your iPhone, tap the Playlists icon at the bottom of the screen; a list of playlists appears. If you don’t have any playlists on your iPhone, don’t sweat it. Just know that if you had some, this is where they’d be. (Playlists let you organize songs around a particular theme or mood: opera arias, romantic ballads, 1980s pop, songs you like to hear when you clean the kitchen, whatever.)
Tap a playlist and you see a list of the songs it contains. If the list is longer than one screen, flick upward to scroll down. Tap a song in the list and it plays.