Organ Eyes
dream pop, lo-fi, shoegaze
Organ Thieves
folk rock, hard rock, heavy metal, reggae, southern rock
Organic Audio
chillout, electronic, electronica, trip-hop
organic stereo
ambient, electronic, post-rock, folk
Organized Chaos
progressive metal, punk rock
Orgone
afrobeat, death metal, funk, soul, technical death metal
Orgy
industrial rock, metal, rock
Orichalcum
goa, goa trance, psychedelic trance
Origin
brutal death metal, death metal, grindcore, technical death metal
Original Dixieland Jazz Band
dixieland, dixieland jazz, jazz
Original Sin
black metal, drum and bass, speed metal
Orion Rigel Dommisse
indie folk, new weird america, singer-songwriter, folk
Orjan Nilsen
melodic trance, progressive trance, tech trance, trance, uplifting trance
Orkrist
black metal, doom metal, folk metal, melodic black metal, symphonic metal