GarageBand for iPad

I have yet to explore all the features of Garageband, on my Mac, and especially on my new iPad.  I am starting with this great youtube tutorial - 40 minutes long - one section at a time.  So far it seems pretty comprehensive and easy to understand.

I think I may be making back tracks for my recorder students, and perhaps my beginning string students.  Who knows what else I will want to do with it?