Brief: "deep depth of raw black metal mixed with noise aesthetics" — user gave four concrete reference threads to chase down: (1) "Funeral Stench" archives on Rate Your Music, (2) early Posh Isolation black metal, (3) a Russian label he called "Horrible Room," (4) Youth Attack Records' black-metal wing (namechecking Haxan and Grinning Death's Head).

Process note: The first research pass badly over-delegated — four parallel research agents each spun up further nested sub-agents (5+ each), most of which hit API rate limits and returned nothing. That burned a chunk of budget for very little signal. I cut it off and finished the verification myself directly with WebSearch/WebFetch + the Spotify top-tracks command, which is what actually produced the real list below. Lesson: for narrow discography-verification work, direct searches beat multi-layered delegation.

Thread 1 — "Funeral Stench" (RYM archive): Searched extensively for an RYM list/chart called "Funeral Stench." Does not exist — no RYM list, curated chart, or informal archive by that name turned up. "Funeral Stench" IS a real Metal Archives band entry (metal-archives.com/bands/Funeral_Stench/32490) — but it's tagged death metal, from Moscow, Russia, formed 2002, now split up, with no discography, Bandcamp, or Discogs presence findable. Not raw black metal, not usable. Dead end. Collision #1: "Funeral Stench" is also just a song title by Vesen (Norwegian black/thrash) on "Desperate Mindless Aggression" (2009) — a track, not a band, coincidental phrase match. Collision #2: "Mass Funeral Stench Split" is a 2026 split-tape title between Druid Stone and Tumultuous Ruin — again a coincidental phrase, not the referenced archive. Verdict: could not verify the user's specific memory of an RYM "Funeral Stench" archive. Substituted with genuinely verified raw/lo-fi black metal classics that match the "deep archive of raw BM" spirit instead (Xasthur, Leviathan, Striborg, Ildjarn, Judas Iscariot, Beherit, Paysage D'Hiver, Vasaeleth, Antediluvian, Weregoat, Cultes des Ghoules, Darkspace, Urfaust, Nortt) — all cross-checked as real via Spotify's own catalog (top-tracks command returns actual track titles, so no invented titles snuck in).

Thread 2 — Early Posh Isolation black metal: Posh Isolation confirmed real, a Copenhagen noise/power-electronics/coldwave label, est. 2009, run by Christian Stadsgaard & Loke Rahbek. Checked Discogs (discogs.com/label/154437-Posh-Isolation) and the roster (Croatian Amor, Lust For Youth, Damien Dubrovnik, Sexdrome, Vanity Productions). Extensive searching found no confirmed black metal release on Posh Isolation. Loke Rahbek's other projects check out as ambient / synthpop / IDM / power electronics on RYM and Discogs — none tagged black metal. One unconfirmed lead (a Discogs credit calling Sexdrome a "black metal-tinged punk group" in an aggregator summary) could not be verified against a primary source (Discogs/RYM blocked automated fetches with 403) — flagged as unverified and NOT used, per the rule against guessing. Verdict: the "early Posh Isolation BM" premise doesn't check out as a literal label discography. Substituted with real, well-documented noise/black-metal hybrid acts that occupy the same "blackened noise" continuum the user is clearly after: Sutekh Hexen, Gnaw Their Tongues, Aluk Todolo (Wold was also researched and fits the aesthetic perfectly but could not be found on Spotify at all — dropped) — all confirmed via Spotify top-tracks and cross-referenced against genre write-ups describing exactly this "black noise" hybrid style (a documented micro-genre spanning raw/orthodox BM, industrial/noise, and ritual ambient).

Thread 3 — Russian "Horrible Room" label: The label is real — Horrible Room, a small Russian DIY cassette label (Discogs: discogs.com/label/1461062-Horrible-Room; Bandcamp: horribleroom.bandcamp.com; Metal Archives: metal-archives.com/labels/Horrible_Room/51459). Roster is mostly tiny noise/power-electronics micro-tapes (Nice Guy, Blackmagnum, Hank Hill Propane Review, Yard Boy, Voidgarden, AN, White Scum, Needle Fetish), including a Voidgarden/AN split tape (HR-009, 2019, edition of 10). None of that specific roster has any real Spotify presence (checked AN, Voidgarden, Blackmagnum, Spidvich — all ARTIST_NOT_FOUND, or false-positive matches: a Spotify "VoidGarden" exists but is followers=2/popularity=0 and unclear if it's even the same project, so it was left out rather than misattributed; "Spidvich" resolved to a totally unrelated Vladimir Vysotsky search hit — discarded). Verdict: Horrible Room itself is real but not represented on Spotify at all — a genuine dead end for a streaming playlist. Substituted with real, verified Russian raw/atmospheric black metal that fits the same underground-tape aesthetic: Grima (Siberia, now signed to Napalm but rooted in the raw/atmospheric scene), Frozenwoods (Siberian raw/forest BM), Wintaar (Ural region raw/atmospheric BM) — all confirmed via Spotify top-tracks with real track titles pulled directly from their catalogs. (A parallel sweep also turned up other real Russian/CIS labels — More Hate Productions, Solitude Productions/BadMoodMan Music, Satanath Records, Depressive Illusions Records (Ukraine), Kryrart Records — none of which had catalog artists confirmable on Spotify either, so they stayed out of the final list but are noted here for completeness.)

Thread 4 — Youth Attack Records: Haxan, Grinning Death's Head: Grinning Death's Head confirmed real, on Youth Attack Records since a debut LP (Dec 25, 2009), through "Black Sun Rising" (cassette demo, 2011), "Blood War" (2017), up to a 2025 self-titled LP. Georgia (US), founded 2007 by J. Wood. Has a Spotify artist page (open.spotify.com/artist/4qsl57kl8Fn4TFmnkHvLFF) — pulled real tracks "Year of the Snake" and "Blood War" via top-tracks. Häxan confirmed real: the Youth Attack release "Häxan" (April 25, 2015, youthattack.bandcamp.com/album/h-xan), 5 tracks: Intro, Witches Oath, Conjurer of the Spectral Abyss, Grand Denunciation, Outro. On Spotify as "Häxan" with a different-looking top-tracks catalog (Death of Me, Skeletons, Thirteenth Hour) — likely a later release under the same act/Spotify page; used the verified Spotify catalog rather than guessing the 2015 tracklist blind, per the guardrail rule against inventing titles. Cross-checked to make sure the Spotify "Häxan" id (2MBeYzcgFfNxgZ9YFh94gJ) isn't one of the several unrelated same-name bands on Metal Archives (Haxxan, Häxanu, Haxan Death Metal). Also flagged: "Häxan, ...or Medieval Witchcraft and Infanticide..." is a totally separate Cultes des Ghoules album (different band, coincidental reuse of the 1922 film's title) — Cultes des Ghoules was included on its own merits, not because of the name overlap. Also pulled from the same Youth Attack roster: Ancestors — Bandcamp copy describes their "In Death" LP as "raw hardcore and lo-fi black metal" — confirmed real, on Spotify, track "Antler Wings" verified via top-tracks. "Arts" (also on Youth Attack, noise/BM-adjacent per bandcamp copy) was researched but not found on Spotify — dropped.

Final build: Built a 47-line candidate file (roughly 1.7x the ~27-track target), ran spotify.mjs dry-run. Tool returned 27 OK / 20 DUPE (it caps at one track per artist by default; two candidate tracks per artist had been submitted as backups, so the seconds all came back DUPE as expected, not an error). All 27 OK tracks are single-artist matches with no MISMATCH or XX — every title came from Spotify's own top-tracks catalog rather than being guessed. Created the playlist with these 27 tracks, public visibility, and a descriptor under the 250-character limit.

Final artist roster (27 tracks / 27 artists): Häxan, Grinning Death's Head, Ancestors, Sutekh Hexen, Gnaw Their Tongues, Aluk Todolo, Xasthur, Leviathan, Striborg, Ildjarn, Judas Iscariot, Krieg, Ash Pool, Nortt, Beherit, Paysage D'Hiver, Urfaust, Darkspace, Behexen, Antediluvian, Weregoat, Vasaeleth, Reverorum ib Malacht, Cultes des Ghoules, Grima, Frozenwoods, Wintaar.