Metal genres

Power Glam - Glam metal lyrics with thrash metal instrumentation (with added pop-based catchy hooks and hard rock influence)

Primary Influence: Glam Metal, Thrash Metal, Speed Metal, Pop

Secondary Influence: Hard Rock, Punk Rock, Pop Rock, Arena Rock 

Blackened Grunge/Black-Grunge/Seattle Black Metal (which is a misnomer) - A genre combines grunge's slower tempos, downtuned bluesy riffs, social issues topics and loud fuzz noise on both guitar and bass with black metal's tremolo picking, shrieking vocals and emphasis on atmosphere. Quiet-loud dynamics of grunge are somewhat common. Although blackened grunge has a slower tempo than regular black metal, fast tempos can sometimes be featured in blackened grunge. 

Primary Influence: Black Metal, Grunge, Ambient Black Metal, Atmospheric Black Metal, Blackgaze, Noise Rock

Secondary Influence: Post-Metal, Alternative Metal, Groove Metal

Sometimes however, blackened grunge would also involve Satanic imagery, akin to other black metal genres.

Thrash-Grunge/Thrunge - A peculiar fusion genre of thrash metal and grunge. It takes grunge's fuzzy, downtuned tone, simplicity,, topics (social alienation, self-doubt, abuse, neglect, betrayal, social and emotional isolation, psychological trauma and a desire for freedom), abrasvieness and indie rock feel with thrash metal's speed, aggression, complexity and topics (pessimism, warfare, corruption, injustice, murder, suicide, isolation, alienation, addiction and anti-politics).

Thrash metal and grunge have some things in common: both are punk/metal fusions, both can be raw and both are against mainstream (and ironically, both WERE mainstream at some point).

Grunge's 'quiet-loud' dynamics are rare here (and even when it is used, it's usually power ballad-y), instead there are 'fast-slow' (where musicians switched tempos between sludgy and thrashy ones) and 'simple-complex' dynamics (where musician play two different riffing styles in a same song, very common to have a simple, bluesy guitar solo and then a fast, very complex one).

Primary Influences: Thrash Metal, Grunge

Secondary Influences: Groove Metal, Alternative Metal, NWOBHM, Sludge Metal, Powerviolence, Post-Grunge, Post-Punk, Crossover Thrash, Post-Hardcore

This fusion is a mixture of two blends - the thrash blends styles of Xentrix, Metallica, Megadeth, Slayer, Anthrax, Kreator, Onslaught, Venom and Sodom with a touch of Pantera's groove metal madness, while the grunge side leans heavily toward Tad, Mudhoney, Melvins Alice in Chains, Bleach/In Utero-era Nirvana and early Soundgarden, with a noticable touch of Nevermind-era Nirvana, Pearl Jam, The Smashing Pumpkins, Screaming Trees, Superunknown-era Soundgarden, early Bush, the Pixies and Sonic Youth.

Ah yes we’ve chatted on this one before

Yep.