While Apple did release a dedicated Apple Store app for iPad last November, it has yet to include any promotion or giveaway within that app. You will want to be sure you’re using the standard Apple Store app for iPhone (and yes, you can run it on iPad to redeem the promotional content).
The first view of the app features a list view of categories and featured sections, and U.S. customers should find Apple’s free music promotion toward the bottom of the list. Redeeming the tracks provides you with an offer code and sends you over to iTunes on your iOS device, and the tracks will then download for your consumption.
Previously, Apple has featured free content including Tetris, a fitness app, and more in its retail shopping app. We originally reported Apple’s plans to begin giving away content to Apple Store app users to promote the shopping experience last July.