on
ambient, hardcore punk, straight edge
On The Last Day
emocore, post-hardcore, screamo
One Buck Short
pop, pop punk, punk rock, rock
One Drop
punk rock, reggae, rock, ska
One Less Reason
alternative metal, alternative rock, hard rock, rock
One Man Army
death metal, melodic death metal, punk rock
One More Girl
country, pop, pop rock, singer-songwriter
One Republic
alternative rock, pop rock, rock
one sonic society
christian rock, contemporary christian
OneRepublic
alternative rock, pop rock, rock
Oniric
cabaret, dark cabaret, neofolk
Only Crime
hardcore punk, melodic hardcore, punk rock
Onslaught
heavy metal, metal, speed metal, thrash metal
Onyx
gangsta rap, hip hop, rap
Onyx Eyes
gothic metal, symphonic metal
Ooklah the Moc
dub, reggae, roots reggae
Oomph!
industrial metal, metal, rock