Doom metal — The Duration Engine

Doom metal — The Duration Engine — from Below a Hundred Hertz.

Doom metal — The Duration Engine

Hold the note until its fundamental exists. Doom is slow for a reason that is measurable rather than atmospheric — below about 60 Hz a note needs real time before the ear can hear it as a pitch at all.

The acoustics, which are the whole argument

Pitch perception has a floor and it is close to 30 Hz. Krumbholz, Patterson and Pressnitzer, in the Journal of the Acoustical Society of America in 2000, found discrimination deteriorating rapidly across the octave from 40 down to 20 Hz, with the underlying temporal mechanism limited to analysis windows of less than about 32 milliseconds. A 30 Hz cycle takes 33 ms. The window barely spans one cycle.
And you need several cycles. Hsieh and Saberi, in Psychonomic Bulletin & Review in 2016, found four cycles sufficient for absolute pitch identification — and, importantly, that higher-frequency tones are identified more accurately than low ones even at matched cycle counts. Low notes are intrinsically harder to pin down, cycle for cycle.
Do the arithmetic and doom's tempo stops being a stylistic choice. At 40 Hz one cycle is 25 ms, so four cycles is 100 milliseconds before you have a chance at hearing a pitch — and that is the optimistic figure. A palm-muted sixteenth note at 200 BPM lasts 75 ms. It cannot contain a 40 Hz pitch. It can only contain a thud.
Be careful with the causal claim, though. Neither paper mentions doom metal, and tempo is also driven by riff legibility, decay time and genre convention. The honest statement is that the acoustics make slow tempo necessary for low fundamentals to be audible as pitches, not that they are the only reason doom is slow.

Sustain, not decay — the practitioners correct the framing

Stephen O'Malley of Sunn O))) rejects the obvious word. Asked about decay, he answered: “Well, because it doesn't stop. Decay leads to an end. 'Sustain' is actually the word which is more appropriate.” The aim is a “physical sound mass” — and he is blunt that it is not a volume contest: “It's not about loud and loudest. It's about scale and size.”
So the two wings of doom are doing opposite things with the same duration. Riff-based and funeral doom genuinely let a chord ring out and die, making the decay the event. Drone doom uses amplification to defeat decay so the note never resolves. Do not apply one description to both.
Dylan Carlson's method on Earth 2 is documented and disarmingly plain: take “a Slayer-style riff and play it for 20 minutes at half speed,” with La Monte Young cited as the influence. Sustain came from distortion plus overdubbed layers, some of them clean, not from distortion alone. Thirty-minute analogue reels forced the long tracks to be spliced.
And Sunn O)))'s distortion is a pedal, not an amp. The documented chain is vintage early-seventies Sunn Model T heads plus Ampeg SVT heads and 8x10 bass cabinets, with a ProCo RAT pushing the valves. Greg Anderson: “The third member of the band is the amplifiers!” Guitars go as low as drop A.

Sabbath, corrected

Iommi lost fingertips, not fingers — the tips of the middle and ring fingers of his right hand, which is his fretting hand, at seventeen on his last day at a Birmingham sheet-metal factory. He made thimbles from a melted-down washing-up-liquid bottle and covered them with leather cut from an old jacket.
The strings story is better than the tuning story. Light-gauge guitar strings did not exist commercially, so he used banjo strings until Picato began making them around 1970.
And the detuning had two reasons, not one. Lower tension eased the damaged fingertips and produced the bigger sound he wanted. “He only detuned because of his fingers” is an oversimplification the sources do not support.
Master of Reality is not a uniformly C♯ record. Only three tracks are documented at three semitones down — “Children of the Grave,” “Lord of This World,” “Into the Void” — and at least one source puts others in D standard. Treat the blanket claim as contested. Geezer Butler's exact bass tuning relative to Iommi is likewise unresolved across sources.
Butler and Iommi ran the same amp: a Laney LA100BL, where “BL” stands for Bass or Lead because it was built to be either.

The tritone, and the bass as a lead voice

The church never banned the tritone. There is no evidence of prohibition, excommunication or punishment — a historian quoted on the subject puts it flatly: “no one seems to have been tortured, imprisoned, or excommunicated for a musical arrangement, all internet assertions to the contrary notwithstanding.” The real thing is the counterpoint mnemonic mi contra fa est diabolus in musica, a voice-leading teaching rule, and that phrasing is not well attested until the eighteenth century.
Doom has two genuinely different bass traditions and they coexist. One is unison — guitars and bass playing the same riff for a monolithic wall. The other is the bass as an independent voice, which is what Butler is actually famous for: “Because our music was so uncluttered, there was space for the bass to riff.” He modelled parts on Chris Squire and Jack Bruce, and Ozzy's reaction to the “War Pigs” bass was “what the hell is that?”
Om is the extreme case and it settles the question. Al Cisneros's band ran three albums with bass, drums and vocals and no guitar at all, making the bass the sole harmonic, melodic and rhythmic instrument. His technique is fingerstyle, modelled on reggae — Aston Barrett and Robbie Shakespeare — and he plays near the neck rather than the bridge for better pressure transfer through the cone.
Dopesmoker was spliced from three reels because analogue tape maxed out at 22 minutes, and it exists in three lengths: Jerusalem at about 52 minutes, the 2003 Dopesmoker at 63:31 and the 2012 remaster at 63:34. Matt Pike's account of the amps — custom green Matamp GT120 MV heads “designed to be so loud, no one from the band was capable of going into the same room as them” — and the roughly $75,000 spent on them are his own figures, not audited ones.

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