This beat is badass. Love what you've done with the drum sounds here.
I like a lot of your synth sounds. Your backing guitar is spot on. LOVE it.
If I have any constructive criticism at all, it's this: When creating a lead guitar, if you mean for it to sound realistic, you really must use pitch bend. This track does sound great as it is, don't get me wrong, but a live guitarist utilizes a technique where he stetches the guitar strings along the fretboard to add soul and depth to his phrasing. And this method can absolutely be recreated in Music Generator to keep the guit sounding natural and non-synthy. Try listening to some of the guitar masters; Your Kirk Hammets and Joe Satrianis and Stevie Ray Vaughns and the like. The really tricky thing about creating a lead guitar part is that an electric guitarist doesn't play like one would another instrument. It's not straightforward. When an electric guitar lead is done correctly, it sounds more like someone is singing than playing an instrument.
My own method is to create a phrase in flat, straight-on notes and then add bends and shifts to the existing phrase. A guitarist will often add an upward bend of about a half step to the beginning of the first note in a phrase. So it looks a little like this:
Play around with it. It really adds some life to your lead parts. This same technique can be used to make a synth lead really pop. Check out a guy named Jordan Rudess here for a little inspiration if you like. The opening of this vid is ALL keyboard, no guitar: