Previous deal listed here expired on 07/11, this is not a duplicate. However if you already redeemed this offer, you cannot redeem it again.
How to redeem your code for $2 in Amazon MP3 credit:
1. Prior to making a purchase, click the button below, enter the code HEARTMP3, and click the "Apply" button. Your $2 credit will be automatically applied to your account.
2. If you received a confirmation that your code has been entered successfully, your $2 credit is now in your account and will remain there until it has been applied towards eligible purchases or until it expires at 11:59 p.m PDT on July 23, 2012. If you receive an error entering your code, be sure to check that you've entered the code correctly and be sure that the promotion is still valid and has not expired. If you still receive an error, contact Customer Service via Amazon MP3 Support.