This is Phase the Blood, a short piece I put together in response to the Fresh Pair Junto prompt, which asked for the combination of two (possibly disparate) strong influences.
I chose Slayer and Steve Reich. The piece is a Slayer-style riff played on one guitar and a version of that riff that has an extra half beat so that the two parts are not in phase, Steve Reich-style.
Slayer is a band I got into when I was 15 (I'm now 46) and saw live over ten times. I don't think any other artist has ever hit the parts of my brain that process music that hard.
I try not to write Slayer-like riffs because there is a huge event horizon that will pull your riff into the "like Slayer but not as good." Almost all first-generation American death metal bands were influenced by Slayer, so it's a hazard most of them faced. Bands like Suffocation are able to take that Slayer pitch sense and produce riffs that were truly transformative. Some others weren't and didn't care. For this piece, I decided not to care on account of its purpose.
I took that riff and put it in a format introduced to me by Steve Reich. I first heard his piece Come Out in a college class. I think it either Intro to Music Technology or Computer Sound Processing. At that time, I hadn't heard any electronic music that wasn't dance-oriented. I hadn't heard much classical music from the 20th century or later, either. I was pretty stunned that two tape loops going out of phase could produce something like that.
I then went to Dr. Wax and bought a CD with more of his phase music. I remember it having both Come Out and Violin Phase on it, but I can't find that on Discogs, so maybe I'm misremembering. Regardless, I heard Violin Phase, in which a recording of a violin is played with a different length version of itself to create all sorts of emergent patterns.
Here, I'm doing something similar. I have two guitars playing two riffs, one of which is two 4/4 bars long and the other which is almost the same but it has a 4/4 bar and 9/8 bar. To avoid making one of the guitars sound like it's right and like the other one doesn't know what it's doing, I put on two drum parts to go with each riff.
I've done phase pieces before, but always via purely electronic means because that just seemed like the natural way to do it. I think the phase format does work well with physical playing, so I'll probably do more of it.