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
