Returning iPod MediaItemCollection based on index

Question

Hi, I'm currently working on an app that accesses a user's iPod library to generate data. The order is something like this:

1. Do a generic MediaQuery that returns everything
2. Iterate through MediaItemCollection and save title/artist info into an array
3. Clear MediaItemCollection and retrieve required items later via title query

However, this becomes a problem when the user has a large library and an out of memory exception is thrown. So I'm wondering if it's possible to actually retrieve the MediaItems in chunks via some sort of index or ID instead. Which means I'll maybe load a chunk of 20 songs at a time, saving the info I need, clear the collection, then load the next 20 songs.