- O
- OO
- OO
- OO
- OOAF
- OAFOak
- OakObe
- ObeObo
- OboOca
- OcaOce
- OceOct
- OctOct
- OCTOdd
- OddODE
- ODEOdu
- Oduof
- OfOff
- OffOfM
- OfnOgu
- OOh
- OhOho
- OHoOje
- OjeOKA
- OKAOkt
- OkuOla
- OlaOld
- OldOle
- OleOli
- OliOli
- OliOll
- OllOls
- OlsOma
- OmaOme
- OmeOmm
- OmnOn
- OnOnd
- OndOne
- OneOne
- OneOne
- OneOni
- OniOnl
- onlOny
- OnyOos
- OotOpe
- OpeOpp
- OppOr
- OrOra
- oraOrb
- OrbOrc
- OrcOrd
- OrdOrg
- OrgOri
- OriOri
- OriOrl
- OrlOrp
- OrpOrq
- OrqOrt
- OrtOsa
- OsaOsc
- OscOsk
- OskOss
- OssOta
- Oti
- OtiOtt
- Ott
- Our
- OurOut
- OutOut
- OutOut
- OutOve
- OveOve
- OveOwe
- OWEOwl
- OwlOxm
- oXnOzc
- OzcOzu
- Ozuozz
- O’Halloran, Dustin
- O’Halloran, Dustin & Bertelmann, Volker
- O’Halloran, Dustin & Gyða Valtýsdóttir
- O’Halloran, Dustin & Senti, Bryan
- O’Halloran, Dustin & Siggi String Quartet
- O’Halloran, Dustin, ACME String Quartet
- O’Hara, Catherine
- O’Hara, Jamie
- O’Hara, Jill
- O’Hara, Kelli
- O’Hara, Kelli, Pasquale, Steve & Company
- O’Hara, Mary (Irish soprano and harpist)
- O’Hara, Mary Margaret
- O’Hara, Maureen
- O’Hara, Paige
- O’Hara, Paige, White, Richard and Chorus
- O’Hearn, Patrick (American bass guitarist and keyboardist)
- O’Hora, Ronan, Royal Philharmonic Orchestra, Carney, Jonathan
- O’Jays, The
- O’Kanes, The
- O’Kaysions, The
- O’Keefe Music Foundation (Music School)
- O’Keefe, Danny
- O’Keefe, Johnny
- O’Keefe, Laurence & Benjamin, Nell
- O’Keefe, Laurence & Benjamin, Nell
- O’Landa Draper and the Associates
- O’Leary, Ben
- O’Leary, Eamon
- O’Malley, Katie
- O’Meara, Jo
- O’My’s, The (Chicago rock/soul duo)
- O’Neal, Alexander
- O’Neal, Alexander feat. Cherrelle
- O’Neal, Alexander featuring Cherrelle
- O’Neal, Maddy
- O’Neal, Maddy & Def3
- O’Neal, Maddy & LIINKS
- O’Neal, Maddy & MOONZz
- O’Neal, Maddy, An-Ten-Nae & Wolf, Torii
- O’Neal, Maddy, Shylow & Lari, Britt
- O’Neal, Patrice
- O’Neal, Shaquille (performs as DJ Diesel aka Diesel)
- O’Neil, Kris (trance)
- O’Neil, Melissa
- O’Neil, Tara Jane
- O’Neill, Ellie (Irish singer)
- O’Neill, Lisa (Irish singer)
- O’Neill, Michael (jazz guitarist based in Los Angeles)
- O’Neill, Michael (Canadian (B.C.) composer, performer)
- O’Neill, Sharon
- O’Neill, Terry (Irish balladeer, "A Nation Once Again" among others)
- O’Phantom
- O’Quin, Greg
- O’Reilly, Ahna, Pasquale, Steve & The Robber Bridegroom 2016 Ensemble
- O’Reilly, Emmett (Respire)
- O’Reilly, Kevan
- O’Reilly, Marty & the Old Soul Orchestra (acoustic folk/blues band)
- O’Reilly, Melanie
- O’Reillys and the Paddyhats, The
- O’Riley, Christopher (American pianist)
- O’Rion, Alex
- O’Riordan, Dolores
- O’Rourke, Declan
- O’Rourke, Jim (US musician & producer, b. 1969)
- O’Rourke, Jim feat. Aoyama, Yōichi
- O’Rourke, Jim feat. Kosaka, Chu
- O’Rourke, Jim feat. Moore, Thurston
- O’Shaughnessy, Ryan (Irish singer-songwriter and former actor)
- O’Shine, Simon & Navel, Adam
- O’Shine, Simon & Navel, Adam
- O’Shine, Simon & Romel, Ahmed
- O’Shine, Simon Feat. Eskova
- O’Shine, Simon feat. Eskova
- O’Sullivan, Daniel (British multi‐instrumentalist and composer)
- O’Sullivan, Gilbert
- O’Sullivan, Gilbert & Lee, Peggy
- O’Sullivan, Gilbert feat. Hucknall, Mick
- O’Sullivan, Gilbert feat. Tunstall, KT
- O’Sullivan, Gilbert with Lee, Peggy
- O’Sullivan, Niall (Irish trumpeter)
- O’Sullivan, Paul, Band, The
- O’Toole, Rich
- O+S
- o0o
- O2 Wolf
- O3ohn
- O5 & Radeček
- Oaf1
- OAFF
