Obsolete Theory

Death Metal

2 Albums

Oceana

Doom Metal

2 Albums

Odd Dimension

Progressive Metal

3 Albums

Odyssea

Power Metal

2 Albums

Okkultum Magnificentia

Black Metal

2 Albums

Olamot

Brutal Death Metal

2 Albums

Oltretomba

Black Metal

2 Albums

Omega Zero

Progressive Metal

1 Album

Omnia Malis Est

Black Metal

1 Album

Onferno

Black Metal

1 Album

Ontborg

Melodic Death Metal

3 Albums

Open Fire

Nu Metal

1 Album

Opera IX

Black Metal

12 Albums

Ophiocordyceps

Brutal Death Metal

3 Albums

Orange Blossom Jam

Metal

1 Album

Orcrist

Black Metal

5 Albums

Organ

Doom Metal

2 Albums

Orgrel

Black Metal

2 Albums

Ottobrenero

Progressive Metal

1 Album

Ottone Pesante

Avant-Garde Metal

7 Albums

OTUS

Post-Metal

1 Album

Pachiderma

Doom Metal

1 Album

Palkosceniko al neon

Metalcore

7 Albums

Pandaemonium

Power Metal

3 Albums