| Orquestra à Base de Sopro de Curitiba | 0 | 0 |
| Orsino Ensemble | 0 | 0 |
| Orsolino Wind Quintet | 0 | 0 |
| Orsolya Korcsolán | 2 | 0 |
| Orson Claeys | 0 | 0 |
| Orsoniks | 0 | 0 |
| Ort Ensemble Wuppertal | 0 | 0 |
| Orthodox Singers | 0 | 0 |
| Ortrun Wenkel | 7 | 0 |
| Ortwin Stürmer | 0 | 0 |
| Orvokki | 0 | 0 |
| Ory Brown | 0 | 0 |
| Os Cariocas | 8 | 0 |
| Os Desafinados | 0 | 0 |
| Os Garotin | 0 | 0 |
| Os Infernais | 0 | 0 |
| Os Músicos do Tejo | 0 | 0 |
| Os Paralamas do Sucesso | 17 | 0 |
| Osaka Municipal Symphonic Band | 3 | 0 |
| Osama Kiwan | 0 | 0 |
| Osamu Fukuzawa | 0 | 0 |
| Osamu Nakamura | 0 | 0 |
| Osanzi | 6 | 0 |
| Oscar Bettison | 0 | 0 |
| Oscar Bohórquez | 1 | 0 |
| Oscar Browne | 0 | 0 |
| Oscar Cash | 2 | 0 |
| Oscar Castro‐Neves | 0 | 0 |
| Oscar Fetrás | 0 | 0 |
| Oscar Fredriks Ceciliakör och sinfonietta | 1 | 0 |
| Oscar Ghiglia | 0 | 0 |
| Oscar Hammerstein II | 10 | 0 |
| Oscar Heiler | 0 | 0 |
| Oscar Jockel | 3 | 0 |
| Oscar Klein | 0 | 0 |
| Oscar Levant | 0 | 0 |
| Oscar Lorenzo Fernández | 0 | 0 |
| Oscar Lysy | 0 | 0 |
| Oscar Moore | 0 | 0 |
| Oscar Mulero | 0 | 0 |
| Oscar Pettiford | 0 | 0 |
| Oscar Shumsky | 0 | 0 |
| Oscar Sixto Bareilles | 0 | 0 |
| Oscar Strasnoy | 2 | 0 |
| Oscar Straus | 8 | 0 |
| Oscar Tarragó | 0 | 0 |
| Oscar de la Torre | 1 | 0 |
| Oscar les vacances | 0 | 0 |
| Oscillotron | 0 | 0 |
| Oshera | 0 | 0 |
| Osian Ellis | 4 | 0 |
| Osie Johnson | 0 | 0 |
| Osipov Balalaika Orchestra | 0 | 0 |
| Osiris Trio | 3 | 0 |
| Oskaal | 0 | 0 |
| Oskar Danon | 2 | 0 |
| Oskar Ekberg | 0 | 0 |
| Oskar Fried | 2 | 0 |
| Oskar Haag | 0 | 0 |
| Oskar Lindberg | 0 | 0 |
| Oskar Merikanto | 9 | 0 |
| Oskar Michallik | 0 | 0 |
| Oskar Morawetz | 0 | 0 |
| Oskar Nedbal | 3 | 0 |
| Oskar Peter | 0 | 0 |
| Oskar Rózsa | 0 | 0 |
| Oskar Sala | 0 | 0 |
| Oskar Szafraniec | 0 | 0 |
| Oskar Wermann | 0 | 0 |
| Oskars Petrauskis | 0 | 0 |
| Oslavio Di Credico | 1 | 0 |
| Oslo Camerata | 3 | 0 |
| Oslo Chamber Music Festival Strings | 0 | 0 |
| Oslo Domkor | 0 | 0 |
| Oslo Filharmoniske Kor | 0 | 0 |
| Oslo Kammerakademi | 0 | 0 |
| Oslo Sinfonietta | 4 | 0 |
| Oslo String Quartet | 0 | 0 |
| Oslo Trio | 0 | 0 |
| Oslo Wind Ensemble | 0 | 0 |
| Oslo kammerkor | 0 | 0 |
| Oslo‐Filharmonien | 73 | 0 |
| Osmo Tapio Räihälä | 0 | 0 |
| Osmo Vänskä | 104 | 0 |
| Osmosis | 0 | 0 |
| Osnabrücker Symphonieorchester | 8 | 0 |
| Osquello | 0 | 0 |
| Ossia | 1 | 0 |
| Ossy Kolmann | 0 | 0 |
| Ossy Renardy | 0 | 0 |
| Ost & Kjex | 0 | 0 |
| Ostinato Ensemble | 0 | 0 |
| Osvaldas Balakauskas | 0 | 0 |
| Osvaldo Berlingieri | 0 | 0 |
| Osvaldo Coluccino | 0 | 0 |
| Osvaldo Golijov | 21 | 0 |
| Osvaldo Lacerda | 0 | 0 |
| Osvaldo Pugliese | 6 | 0 |
| Osvaldo Requena | 0 | 0 |
| Oswald | 0 | 0 |