O! The Joy
emo, math rock, post-hardcore, progressive rock
O'Connor
hard rock, heavy metal, metal
O'Funk'illo
funk, funk metal, funk rock, rock
O-Hum
alternative rock, progressive rock
O-Zone
dance, eurodance, europop, pop
O.R.O.
dance, eurodance, pop rock, rock
O.T. Quartet
dance, electro, electronic
O.V. Wright
deep soul, rhythm and blues, soul, southern soul
Oak Pantheon
black metal, folk metal, post-metal
Oakhelm
black metal, folk metal, pagan metal, viking metal
Oath To Vanquish
brutal death metal, death metal, grindcore, technical death metal
Obie Trice
gangsta rap, hip hop, rap
Obiman
ambient, chillout, electronic, electronica
Obits
indie rock, post-punk, punk rock
Obituary
death metal, metal, thrash metal
OBK
electronic, electropop, synthpop
Obliteration
brutal death metal, death metal
