So they charted the dubstep to bass..
Well, it's certainly not like anything I've ever played before, even that one dubstep RBN song.
You know how a typical bass part is just to lock down the rhythm so the guitar can add its flourishes? This is completely backwards. Guitar and drums hold a steady beat, while the bass changes what rhythm it's playing every three seconds.
Your first playthrough you will have to ignore what you're hearing and focus ONLY on what you see, because your instincts will mess you up. This track switches from 4/4 to triplets to syncopated 16th notes, and it almost never stays the same from measure to measure.
Figuring out the pattern of how they switch is tricky and will keep you on your toes. You'll eventually figure out that it's a pattern that repeats twice every verse and twice every chorus. Once that "clicks" you should nail it.
The amount of challenge and variety would normally get a track a 5, but a track this repetitive would get a 3. I give it a four so it evens out.