Larry,

Yes, you can plug your guitar into the mic/line input jack and play along with your midi file backing tracks--piece of cake, lots of control and it really will sound great.

You cannot record the guitar sounds into the keyboard because it's going through the mic/line input, which is an annalog signal. However, you can connect the keyboard to your computer and record everything that comes out of the keyboard as a WAV file using the instructions I posted at PSR Tutorial.com and get excellent results.

Good Luck,

Gary