Could you pls advise?

I watched the 'new features in BIAB 2015' video and it says now there are 1,000 loops in BIAB 2015.

But how do you use them?

I mean, after you type the chords and generate BIAB, the software will give you a complete arrangement. So why do you need the loops and how will you use them?

A second, related question: I have many samples libraries in Acid wav format. In BIAB 2014, I tried to save them as loops in BIAB, but I failed. The loops did not change their chords. Is it any different in BIAB 2015?

Thank you so much.