Methodology

Each review is attributed to one canonical genre family. The raw MA genre string (e.g. "Thrash Metal (early); Heavy Metal (later)") is processed as follows:

1. Take only the first era — text before the first semicolon.
2. Strip parenthetical era markers: (early), (later), etc.
3. For compound slash genres ("Heavy/Power Metal"), keep the first token only — "Heavy Metal".
4. Normalize to a canonical family (Black Metal → black, etc.) via direct map then keyword fallback.

Families and what they include

• Black Metal — includes Atmospheric, Symphonic, Raw, Depressive, Viking, Pagan
• Death Metal — includes Melodic, Technical, Brutal, Progressive Death Metal
• Heavy Metal — includes NWOBHM, Traditional Heavy Metal
• Doom Metal — includes Funeral, Epic, Atmospheric Doom, Sludge Metal
• Power Metal — includes Symphonic Power, Melodic Power, Epic Metal
• Metalcore / Deathcore — includes Mathcore, Deathcore
• Stoner / Sludge — Stoner Metal, Stoner Rock, Sludge Metal

First-genre policy: compound genres like "Black/Death Metal" are attributed to Black Metal (the first listed). This matches the primary identity the band itself chose.

Split releases: only the first genre slot is used — the review is attributed to the primary band's genre, not duplicated across all bands on the split.