There's a family of scales that sounds like a horror movie deciding whether or not to kill you, and the octatonic scale is its most polite, most evil member. It has eight notes instead of the usual seven, it refuses to pick a key, and it makes even a single palm-muted eighth note feel like a threat. Naturally, Arch Enemy built a bridge riff out of it.
This 36-second clip is me pulling apart the bridge of "Nemesis" — the exact spot where the whole-half diminished scale kicks in and the whole song starts glaring at you. It's palm-muted, it's chromatic, and once you see how the shape is stitched together you'll understand why so many metal riffs quietly steal from this scale.
How the octatonic riff works
The whole-half diminished scale does exactly what the name says: whole step, half step, whole, half, all the way up — eight notes before you repeat. That alternating pattern makes the scale perfectly symmetrical, which is the whole trick. Because it's symmetrical, every shape repeats every minor third: play a figure, slide it up three frets, and it's the same figure a diminished-fifth-flavoured hair scarier. The "Nemesis" bridge leans on exactly that, chaining palm-muted low-string notes with chromatic approaches so the line never resolves and never lets you breathe.
The concrete takeaway: pick one two-string fragment of the riff, learn it clean, then move it up in minor thirds (three frets, then six, then nine). You've now covered the entire scale across the neck without memorising eight separate positions — and your palm muting hand does the heavy lifting for the menace. Keep the mute tight and even; the dissonance only sounds intentional when the rhythm is machine-solid.
Yes, it's a scale built entirely out of tension, which makes it the musical equivalent of a smoke alarm — thrilling for eight notes, unbearable for eight minutes. Use it like Arch Enemy does: in short, murderous doses. Want the PDF and Guitar Pro file so you can loop it until the neighbours move out? It's on my Patreon.