| Orchestra of the Welsh National Opera |
| Orchestra, Pop Du Monde |
| Orchestra, Raksin, David |
| Orchestra Regina |
| Orchestra Sinfonica di Milano |
| Orchestra Tabajara |
| Orchestraccia |
| Orchestral Manoeuvres in the Dark |
| Orchestras Of Carmen Dragon |
| Orchestrating Noise |
| Orchestre André Ekyan |
| Orchestre Association Des Concerts Pasdeloup |
| Orchestre Bobby Cliffton |
| Orchestre Bobby Orchestra |
| Orchestre Charleston Kids |
| Orchestre De Horacio Salgan |
| Orchestre De Jean Boyer |
| Orchestre De La Garde Républicaine |
| Orchestre du Quinn's |
| Orchestre du Théàtre National de l'Opéra-Comique |
| Orchestre du Théâtre National de lOpéra?Comique |
| Orchestre du Théâtre National de l'Opéra de Paris |
| Orchestre Johnny Uvergolts |
| Orchestre Lud Gluskin |
| Orchestre Marius Coste |
| Orchestre Métropolitain du Grand Montréal |
| Orchestre musette Victor |
| Orchestre National de Belgique |
| Orchestre National de Jazz |
| Orchestre National du Capitole de Toulouse |
| Orchestre Philip Green |
| Orchestre Robert Chauvigny |
| Orchestre Super Matimila |
| Orchestre Symphonique de Montréal |
| Orchestre Symphonique Fisyo de Prague |
| Orchestreal Manoeuvres In The Dark |
| Orchid |
| Orden Ogan |
| Order from Chaos |
| Order Of Era |
| Order of Nine |
| Ordinary Peoples |
| Ordo Equilibrio |
| Ordo Rosarius Equilibrio |
| Oré |
| Ore Ska Band |
| Orel |
| Orelha de Pau |
| Orelia Has Orchestra |
| Orelsan |
| Oren Ambarchi |
| Oren Jenkins |
| Oren Lavie |
| Oren Major |
| Orenda Fink |
| Oreo Blue |
| Oreskaband |
| Oresta Cybriwsky |
| Orestes Vilató |
| Orfeh |
| Orfeo |
| Orford String Quartet |
| Orford String Quartet & Armin Electric Strings |
| Organ |
| Organ & Chimes |
| Organ Radio 12 |
| Organ X |
| Organek |
| Organic Audio |
| Orgânico |
| Organisers |
| Organized Konfusion |
| Organized Noize |
| Organoclorados |
| Organs and Chimes |
| Organs & Chimes |
| Orgi |
| Orgi69 |
| Orgone |
| Orgullo Azul y Oro |
| Orgy |
| Orhan Ekin |
| Orhan gencebay |
| Orhan Hakalmaz |
| Orhan Helvacıoğlu |
| Orhan Ölmez |
| Orhan Söğüt |
| Orhun Kerem |
| Ori Dagan |
| Oriana |
| Orianthi |
| Oric |
| Orient Pearl |
| ORIENTA |
| Oriental Echo Ensemble |
| Oriente |
| Orietta Berti |
| Origa |
| Origami Amassado & Winston Churchill Rangel |
| Origen |
