Ex. 1, a single-note riff from “I Thanitos” (which will appear on my band Outworld’s soon-to-be-released debut), features only two different notes per bar, and the rhythm—not unlike some jackhammers—is straight-up one-e-and-a sixteenth-notes all the way through. But the pattern of alternation between the two pitches (the rhythm that repeats in each bar) is what, I think, gives the riff its moxie. It’s written for 6-string here, but if you really want to give the lick muscle, play it down a string—that is, down a fourth in pitch—as I do on my 7-string.
This approach is also a blast in odd meters. Add a note and add one beat per measure, and you might come up with a 5/4 three-notes-per-bar riff like Ex. 2, which is also from “I Thanitos.” Honestly, analyzing rhythms is not my strong suit. That’s because rather than time signatures, I prefer to think in rhythmic pulses. What I mean by this is that instead of counting the numbers one through five for every four sixteenth-notes as the time signature suggests, I focus on the riff’s phrasing. I count each bar’s 20 pulses like this: one-two-three, one-two-three, one-two-three, one-two-three, one-two, one-two, one-two-three-four. As you’ll see when you get more familiar with this lick (which, by the way, I also play down a fourth on the recorded version), that pattern of counting corresponds closely with the riff’s melodic contour.