MasterCard gift cards are used just like credit cards and are accepted everywhere that MasterCards are accepted, including iTunes.
iTunes is Apple software available for download that gives you access to millions of songs, music videos, television shows, movies, iPhone applications, and podcasts. Products on iTunes can be bought using a credit card or an iTunes gift card, purchased through Apple online or at one of its stores. You can use a MasterCard gift card to purchase products on iTunes.
Instructions
Setting up an Apple Account
1. Download iTunes on to your computer from the Apple website.
2. Open iTunes. On the left hand side of the screen, choose "iTunes Store." Click on "Create Account" on the right hand side of the screen.
3. Read through the terms and conditions, check the agree box and click continue. Complete the form for your name, and create an Apple ID.
4. Enter valid payment information. This can be done with your MasterCard gift card; enter information just as if it were a credit card.
Using the Card on iTunes
5. Open iTunes and go to the iTunes store. Click on "account" and input your user ID and password.
6. Add gift card information. If you didn't do this when you created your account, click on "Edit Payment Information" on your account page. Enter your name, the card number, the expiration date and security code. Click "done". Skip this step if you already added the gift card during account set up.
7. Browse through iTunes using menu options at the top of the iTunes store screen. Double click on the title of the item to show its information. Hit the "Purchase" button to buy the item. The product will automatically download to your iTunes library. When your gift card no longer has any money on it, iTunes will notify you that you need to update your payment information. This means it wasn't able to process the gift card.