I always love a straight rock groove with the blues, because when we think about the blues it's usually a shuffle feel. In "Shadow Walker," I played off the groove from Free's "Walk In My Shadow" to show you a cool riff just using the pentatonic scale. On this one, I'm going for a classic overdrive guitar sound using a strat into an overdriven tube amp. It's important to not get too crazy with the amount of gain as it can obscure the riff and lose a lot of its attack—some people may disagree, but hey, this in my course! ;-)
As we can see, the riff basically repeats itself throughout the whole tune. The challenge is to continue playing the riff, keeping it locked in, fighting off the will to go off too much. The riff IS THE TUNE and it's awesome as it is, so don't mess with it! In my 30 Authentic Blues Grooves course, I basically say the same thing about the Sonny Boy Williamson tune "Checking Up On My Baby," which is very similar. Keep it going, and keep it grooving. That's the real challenge!