Question

I’m developing new app that uses webpage to pay for melody. I don’t want to use in-app purchase cause of some reasons. So my questions is : can i use other web-page to pay for melody so user can listhen for this melody. Thank you

Answer 1

The App Store Review Guidelines are pretty clear about this:

11.2 Apps utilizing a system other than the In App Purchase API (IAP) to purchase content, functionality, or services in an app will be rejected

11.13 Apps that link to external mechanisms for purchases or subscriptions to be used in the app, such as a “buy” button that goes to a web site to purchase a digital book, will be rejected

11.14 Apps can read or play approved content (specifically magazines, newspapers, books, audio, music, and video) that is subscribed to or purchased outside of the app, as long as there is no button or external link in the app to purchase the approved content. Apple will not receive any portion of the revenues for approved content that is subscribed to or purchased outside of the app

So the answer is: Yes you can create a web site where a user can purchase melodies that are downloaded to your app. But you are not allowed to mention that web site in your app. Amazons Kindle app does exactly this.

Though, you are not amazon. So you won’t sell a lot of melodies when you choose that method.
If your app does not mention the way to get additional melodies people won’t open safari to go to your website to figure out if there are more. Just use IAP.