We tune to standard, but a half-step down, and then the lowest string is dropped down to an A#. It’s A#–G#–C#–F#–A#–D#. It’s cool because you can play riffs that would work in standard, but what would be just a power chord now has an extra low octave to it, which really changes the whole texture.
I think I first noticed a similar tuning in the song “Prison Sex” by Tool, and I remember that song really jumped out at me. When I heard that song, I thought, “That’s got to be a bass,” but it turned out to be a guitar with a low B string. I think Soundgarden’s “Rusty Cage” and some other songs on
Badmotorfinger are also in that tuning [B–A–D–G–B–E].
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https://www.premierguitar.com/artic...-brodsky-and-nick-cageao-prog-punk-alchemists)