The Nuns
gothic rock, new wave, post-punk, punk rock
The Nutmegs
doo wop, oldies, rhythm and blues, soul
The O.C. Supertones
christian rock, christian ska, ska
The Oath
black metal, doom metal, heavy metal, metal
The Obsessed
doom metal, heavy metal, stoner metal, stoner rock
The Ocean
post-metal, progressive metal
The Offs
funk, punk rock, reggae, ska
The Offspring
alternative rock, punk rock, rock
The Old Dance School
celtic, jazz, world music, folk
The Old Dead Tree
death metal, doom metal, gothic metal, metal, progressive metal
The Olympics
funk, northern soul, pop, soul
The One AM Radio
electronic, indie pop, lo-fi
The One Hundred
electronic, electronica, metalcore, post-hardcore, rapcore
The One Up Downstairs
emo, math rock, post-rock
The OneUps
8-bit, jazz, video game music
The Ongoing Concept
electronic, metalcore, post-hardcore
The Only Ones
new wave, power pop, punk rock
The Open Mind
garage rock, psychedelic rock, rock