Get music and other audio content onto iPad:

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