So I'm planning on purchasing the Casio Privia PX 850. One thing I can't find in the specs though is line in connectivity. I go to youtube a lot for backing tracks and I also use Audacity which helps with slowing down tunes, looping chord progressions, etc. All this is super easy if I simply hook up the line out from a laptop into the DP's line in. Is there a way to do this with the PX850 too? Thanks!