Operadyse
power metal, symphonic metal
Operatic
alternative rock, emo
Operatika
gothic metal, metal, power metal, symphonic metal
Operation Ivy
punk rock, ska, ska punk
Operator
alternative metal, grunge, hard rock, post-grunge, rock
Opeth
death metal, metal, progressive death metal, progressive metal
Ophélie Winter
french pop, pop
Ophicvs
black metal, heavy metal, speed metal
Ophidian
darkcore, gabber, hardcore techno
Ophis
death metal, doom metal
Ophthalamia
black metal, doom metal, melodic black metal
Ophydian
alternative metal, heavy metal, melodic metalcore
Opiate For The Masses
alternative metal, industrial metal, metal, rock
OPIUO
breakbeat, dubstep, glitch
Opolopo
broken beat, electronic, funk, nu jazz, soul
Oppenheimer MKII
new wave, synthpop
Opposition
new wave, post-punk
Optimo
electro, electronic, techno
Optimum Vulnerability
dance, electronic, trance
Optimus Rhyme
hip hop, nerdcore, rap
Opus 5
art rock, jazz, progressive rock
Opus Avantra
avant-garde, progressive rock
Opus Däi
alternative rock, progressive rock, rock
Opus III
chillout, dance, electronic, techno
Opus Orange
indie pop, surf rock, folk
Oral Bee
hip hop, rap, rock
Orang-Utan
classic rock, hard rock, progressive rock, psychedelic rock
Orange 9mm
alternative metal, post-hardcore, rapcore, rock