- O
- oO
- OO
- OO
- OOak
- OakObe
- ObeOBL
- OBL
- Oce
- OceOct
- OctOda
- ODAode
- odeOdi
- OdiOes
- OesOff
- offOff
- OffOgr
- OgrOh
- OhOi
- OiOjo
- OjoOke
- OkeOl
- OlOld
- OldOld
- OldOli
- OliOli
- OliOll
- OllOlv
- OlyOma
- OmaOmi
- OmiOMY
- OMYOnd
- OndOne
- OneOne
- OneOne
- OneONL
- ONL
- OnoOok
- OokOpe
- OpeOpi
- OpiOqu
- OquOra
- OraOrb
- OrbOrc
- OrcOre
- OreOri
- OriOri
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- OrpOrq
- Orqort
- OrtOsa
- OsaOsc
- OscOsk
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- OstOte
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- OtrOtt
- OttOur
- OurOut
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- OutOve
- OveOVE
- OVEOwe
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- Ozoozz
- Orquesta Sinfónica Nacional (Argentina - previously known as "Orquesta Nacional del Estado" (1948-1955))
- Orquesta Sinfónica Nacional de Costa Rica
- Orquesta Son de Cuba
- Orquesta Tabaco y Ron
- Orquesta Típica Ciudad Baigón
- Orquesta Típica Fernández Fierro
- Orquesta Típica La Vidú
- Orquesta Típica Misteriosa Buenos Aires
- Orquesta Típica Tanturi
- Orquesta Todos Estrellas (Cuban orchestra (All Stars) with various artists from Egrem label)
- Orquesta Zodiac
- Orquestonga, La
- Orquestra Afro-Brasileira
- Orquestra Alada Trovão da Mata
- Orquestra Àrab de Barcelona
- Orquestra Brasileira de Música Jamaicana
- Orquestra Contemporânea de Olinda
- Orquestra Imperial
- Orquestra Internacional Montgrins
- Orquestra Mirasol (Spanish/Catalan jazz-progressive rock band from the middle 70s)
- Orquestra Ouro Preto
- Orquestra Rena
- Orquestra Voadora (Brazilian brass band)
- Orquestra Was
- Orr, Benjamin (co-lead singer for The Cars)
- Orr, David
- Orr, Marty Christopher (Musical artist from Arkansas)
- Orr, Scott
- Orrall, Robert Ellis (US country singer/producer)
- Orrantia, Hayley (US actress and singer)
- Orrason, Máni
- Orrick, Chris (US rapper, formerly known as Red Pill)
- Orrico, Stacie
- Orrje, Carl, Piano Ensemble
- Orsa spelmän
- Orselli, Folco
- Orsen
- Orsen, Jack
- Orsen, Jack & Taktloss
- Orsenna, Erik
- Orsi
- Orso, L’ (Italian band)
- Orso, L’ con tropicalisti, I
- Orso, L’ con Tropicalisti, I
- Orsolics, Hans
- Orson (00s US power pop band)
- Orson Family
- Orsons, Die
- Orsons, Die feat. CRO
- Orsons, Die feat. Maxim
- Orsons, Die feat. Mine
- ORTA
- Orta, Choco
- Orta, Manuel
- Orta, María (Puerto Rican Christian music singer)
- Orta, Paul
- Ortaç, Serdar
- Ortaçgil, Bülent
- Ortaçgil, Bülent & Kızılok, Fikret
- Ortaçgil, Bülent & Teoman
- Ortak, Svaba (rapper from Austria)
- Ortega, Anthony (jazz saxophonist)
- Ortega, Anthony, Trio
- Ortega, Emanuel
- Ortega, Fernando
- Ortega, Ginesa
- Ortega, Jeannie
- Ortega, Jeannie feat. Papoose
- Ortega, José (designer)
- Ortega, Lindi
- Ortega, Luis "Luca" (Luis Carlos Ortega; Mexican musician, producer, composer/songwriter)
- Ortega, Michael
- Ortega, Miguel (Spanish conductor)
- Ortega, Paco
- Ortega, Palito (singer, actor, record producer, film director, politician)
- Ortega, Rosario (Argentinean singer)
- Ortegon, Sr (José Miguel Ortegón)
- Ortelli, Paolo
- Ortelli, Paolo, Matrix, DJ, Party Boomers feat. C, Jay
- ortensia
- Örter, Hasan Cihat
- Ortero, David
- orteus
- Orth, Marisa
- Orthentix
- Orthodox (Spanish doom metal)
- Orthodox (straight edge hardcore band from Nashville, TN, US)
- Orthodox Celts
- Orthostat
- orti (electronic/electroclash/techno project)
