The author must not be aware of the Apple Enterprise Partner Feed, which is precisely what he wants. It is a massive dump of a highly normalized relational database describing all artists, songs, videos, applications, etc. I've dealt a lot with it: it's a bit of a pain because of how much data there is and now normalized it is, but it's extremely useful. I'm not sure what the requirements are for getting access to it, but you have to apply manually via email.

http://www.apple.com/itunes/affiliates/resources/documentati...