It's not a mod. Rather using the power of mods to give a different and new experience.
The idea is simple. Replace Final Fantasy VII's soundtrack with Final Fantasy XIII's.
When it works, it's uncanny and absolutely amazing.
I have posted a video demonstrating how it works.
http://www.youtube.com/watch?v=_Qx1S4dTUGgPersonally, I think the music actually matches up with the gameplay sometimes and for this reason... I love it so much more.
Should I take more footage and post more? If so I will gladly do it!