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
Orla Gartland
indie pop, singer-songwriter
Orleans
classic rock, pop, rock, soft rock
Orleya
bossa nova, chillout, pop
Orne
doom metal, progressive rock
Ornette Coleman
avant-garde, free jazz, jazz
Orodruin
black metal, doom metal, metal
Orphan Project
hard rock, progressive metal, progressive rock
Orphaned Land
death metal, folk metal, oriental metal, progressive death metal, progressive metal
Orson
indie pop, indie rock, rock
Örsten
electronica, trip hop, trip-hop