Get music and other audio content on to iPhone in the following ways:

• Purchase and download from the iTunes Store: In Music, tap Store.
• iTunes in the Cloud: When you're signed in to the iTunes Store, all of your previous purchases automatically appear in Music.
• Sync content with iTunes on your computer: See the Getting Started section -> Sync with iTunes.
• Use iTunes Match to store your music library in iCloud: See the iTunes section -> iTunes Match.