O   | O Fracas | O Level |
| O Suilleabhain, Micheal | O Toole, Peter | O'Banion, John |
| O'Brien, Conan | O'Brien, Deke | O'Brien, Dermot |
| O'Brien, Erin | O'Brien, Hod | O'Brien, Michael |
| O'Brien, Tim | O'Brien-Docker, Ian | O'Brien-Docker, John |
| O'Bryan | O'Bryant's Washboard Wonders | O'Casey, R. |
| O'Casey, Sean | O'Connell, Helen | O'Connell, Maura |
| O'Connor, Cavan | O'Connor, Des | O'Connor, Hazel |
| O'Connor, Kathie | O'Connor, Sinead | O'Connor, Tom |
| O'Day, Alan | O'Day, Anita | O'Donnell Roger |
| O'Donnell, Al | O'Donnell, Daniel | O'Donnell, Joe |
| O'Donnell, Rosie | O'Dowd, Barry | O'Dowda, Brendan |
| O'Duffy, Michael | O'Farrill, Chico | O'Flynn, Liam |
| O'Gwynn, James | O'Hagan, Sean | O'Hara, John |
| O'Hara, Mary | O'Hara, Mary Margaret | O'Hara, Maureen |
| O'Hearn Patrick | O'Jays, The | O'Kane, John |
| O'Kanes, The | O'Kaysions, The | O'Keefe, Danny |
| O'Keefe, Peggy | O'List, David | O'Meara, Jo |
| O'Neal, Alexander | O'Neal, Johnny | O'Neal, Shaquille |
| O'Riordan, Dolores | O'Rouke, Jim | O'Rourke, Declan |
| O'Rourke, Jim | O'Sullivan, Gilbert | O, Karen |
| O-Town | O. J. Abbott | O.A.R (Of A Revolution) |
| O.C Roberts | O.D, Adrenalin | O.M.D. |
| O.T. Quartet | O.T.T | Oak |
| Oak Ridge Boys, The | Oak, Crooked | Oakenfull, Ski |
| Oakenshield | Oakey & Moroder | Oakley, Gee |
| Oaktown's 3-5-7 | Oasis (Dutch) | Oasis (Mary Hopkin) |
| Oasis (UK) | Oasis (US) | Oates John |
| Oates, Jackie | Oath, The | Obernik, Sam |
| Oberst, Conor | Obey The Brave | OBF |
| Obi | Obie Trice | Obituary |
| Objayda | Obliveon | Obraztsova, Elena |
| Obsession | Obus | Ocasek, Ric |
| Occasion, The | Occasional Few, The | Occasional Five, The |
| Occasional Project, The | Ocean | Ocean Colour Scene |
| Ocean, Billy | Ocean, Humphrey | Oceanic |
| Oceansize | Ochil Players, The | Ochs, Phil |
| Ockeghem, Johannes | Octave One | Octavia |
| October Country | October, Gene | Octopus |
| Odd Man Out | Oddie, Bill | Odds & Ends |
| Odell, Tom | Odetta | Odin |
| Odnoposoff, Ricardo | Odrich, Ron | Odyssey |
| Odyssey | Odyssey, The | Of Arrowe Hill |
| Of Monsters And Men | Of Montreal | Ofarim, Esther |
| Off | Off The Wall | Off With Their Heads |
| Off-Shore | Offenbach, Jacques | Offhooks, The |
| Official Secrets, The | Offshore | Offspring |
| Ofshore | Ofwerman, Rune | Ogan, Gary & Lamb, Bill |
| Ogdens, The | Ogdon, John | Ogerman, Claus |
| Ogermann, Claus | Oggum | Ogura, Kei |
| Oh No | Oh No Ono | Oh Ok |
| Oh Well | Oh Wonder | Oh! Polo |
| Oh' Dev | Oh, Atoms | Oh, Nadia |
| ohGr | OHGR WELT | Ohi Ho Bang Bang |
| Ohio Express | Ohio Players | Ohlsson, Garrick |
| OHM | Ohno, Shunzo | Ohno, Yuji |
| Ohnuki, Taeko | Oil Seed Rape | Oingo Boingo |
| OISIN | Oïstrakh, David | Oïstrakh, David & Igor |
| Oïstrakh, Igor | Oizone | OK Go |
| OK Jive | Okay Temiz | Okereke, Kele |
| Okino, Shuya | Okino, Yoshihiro | Okkervil River |
| Okosun, Sonny | Ol Dirty Bastard | Oladimeji & His Talking Drum |
| Olavide, Begoña | Olay, Ruth | OLD |
| Old And In The Way | Old Crow Medicine Show | Old Fashioned Love |
| Old Gold | Old Man River | Old Metropolitan Band |
| Old Mole Band, The | Old Skool Orchestra | Old Skull |
| Old Swan Band, The | Oldfield, Harry | Oldfield, Mike |
| Oldfield, Natasha | Oldfield, Sally | Oldfield, Terry |
| Oldham Tinkers, The | Oldham, Andrew Loog | Oldham, Will |
| Oldland Montano | Oldland, Misty | Ole Ole |
| Oleander | Olenn, Johnny | Oli Max & D.J. Shapps |
| Oli.P | Olive | Olive Juice |
| Olive, Brian | Olivelawn | Oliver |
| Oliver Books calendars | Oliver Dawson Saxon | Oliver Naylor's Seven Aces |
| Oliver, David | Oliver, Frankie | Oliver, Graham |
| Oliver, King | Oliver, Sy | Oliveri, Nick |
| Olivia De Havilland | Olivia Tremor Control, The | Olivier, Laurence |
| Olivor, Jane | Ollie & Jerry | OLO Worms |
| Olsen, Angel | Olsen, George | Olsher, Lesley |
| Olson, Mark | Olsson, Kai | Olsson, Mats And His Orchestra |
| Olympia Dukakis | Olympic Bouzouki Group, The | Olympic Lifts |
| Olympic Runners | Olympic World | Olympics, The |
| Omar | Omar And The Howlers | Omarion |
| Omartian, Michael | Omartian, Michael And Stormie | OMC |
| Omega | Omega Amoeba | Omega Tribe |
| Omen | Omen III | Omerta |
| Omni Trio | Omsk Russian Ensemble, The | On Offs, The |
| On The Seventh Day | On The Speakers | On/Off |
| Once Again | Once Blue | Onda Del Futuro |
| One | One 2 Many | One Day As A Lion |
| One Dove | One God Universe | One Hand One Heart |
| One Hundred Ton And A Feather | One Hundred Words For Snow | One II One |
| One In A Million | One Lady Owner | One Minute Silence |
| One More Time | One Nation | One Night Only |
| One O'Clock Gang | One The Juggler | One Thousand Violins |
| One Three, The | One To One | One Trive |
| One True Voice | One, Act | One, Arkestra |
| One, As | One-Eyed Jacks | Oneida |
| Onelinedrawing | Oneness Of Juju | OneRepublic |
| OneTwo | Ong, Olivia | Onionhead |
| Only Child | Only If You Call Me Jonathan | Only Lonely |
| Only Ones | Ono, Kim | Ono, Seigen |
| Ono, Yoko | Onono, Ben | Onset, The |
| Onslaught | Onward International | Onyeabor, William |
| Onyx | Onyx, The | Ooberman |
| Oomph | Oosterhuis, Trijntje | Oozay |
| Opa | Opal | Opal Butterfly |
| Opaz | OPE | Open Hand |
| Open In Obscurity | Open Mind, The | Open Road |
| Open Sky | Open, The | Operahouse |
| Operation Ivy | Operator Please | Operators, The |
| Opeth | OPM | OPM (Disco) |
| Oporto | Opossom | Opposition |
| Opsahl & Lindstedt | Optic Eye | Optimist Club |
| Optimum Wound Profile | Optimystic | Opus |
| Opus Dead | Opus III | Opus Int Music Ltd |
| Or-N-More | Ora | Ora, Rita |
| Orabge | Oral Exciters, The | Orange Alabaster Mushroom, The |
| Orange Bicycle, The | Orange Blossom Sound | Orange Can |
| Orange Deluxe | ORANGE GOBLIN | Orange Juice |
| Orange Lights, The | Orange Peel | Orange Power |
| Orange, Richard | Oranger | Orans |
| Orb | Orbidöig | Orbison, Roy |
| Orbit, William | Orbital | Orbo Equitum Solis |
| Orca | Orchestra Baobab | Orchestra Filarmonica Di Roma |
| Orchestra Folklore Di Romagna | Orchestra Luna | Orchestra Makassy |
| Orchestra Of The Opera-Comique | Orchestra Tango Cafe | Orchestre De L'O.R.T.F. |
| Orchestre De La Suisse Romande | Orchestre De Monte Carlo | Orchestre Eddie Roger |
| Orchestre Jazira | Orchestre T.P.O.K. Jazz | Orchid |
| Orchids (60S), The | Orchids, The | Ordeal, DJ |
| Ordinary Boys, The | Ordinary Man | Oregon |
| Orellana, Raul | Orff, Carl | Orford, Martin |
| Organ, The | Organisation | Organization |
| Organized Konfusion | Organum | Orgazmo |
| Orgy | Orianthi | Orielle |
| Oriental Wind | Origin Unknown | Origin, The |
| Original Bedroom Rockers | Original Cast Recording | Original Concept |
| Original Dixieland Jazz Band | Original Mirrors | Original Sound Track, The |
| Original Soundtrack | Original Surfaris | Original Trinidad Steel Band |
| Original Tuxedo Jazz Band, The | Original, The | Originals, The |
| Orioles, Felders | Orioles, The | Orion (Elvis) |
| Orion (Ryan Adams) | Orion The Hunter | Orkest, Metropole |
| Orkestra | Orlando (60s) | Orlando (90s) |
| Orlando Johnson & Trance | Orlando Quartet | Orlando, Tony & Dawn |
| Orleans | Orlons, The | Orme, Le |
| Ormonde Folk, The | Ornadel, Cyril | Ornament |
| Ornamental | Orphan Egg | Orpheus |
| Orphic Soop | Orquesta De Antonio Bustamante | Orquesta Española De Baile |
| Orquestra Casino De Sevilla | Orquestra Sinfônica Brasileira | Orr, Benjamin |
| Orrall, Robert Ellis | Orrico, Stacie | ORS |
| Orson | Orson Family, The | Ortega, Jeannie |
| Ortiz, Cristina | Ortolani, Riz | Orton, Beth |
| Orwell, Paul | Ory, Kid | Oryema, Geoffrey |
| Orzabal, Roland | Os Diagonais | OS Mutantes |
| Os Originais Do Samba | Osa, Sigbjørn Bernhoft | Osborne & Giles |
| Osborne Brothers, The | Osborne, Jeffrey | Osborne, Joan |
| Osborne, Mike | Osborne, Mike & Tracey, Stan | Osborne, Paul |
| Osborne, Tony | Osbourne, Johnny | Osbourne, Ozzy |
| Oscar | Oscar Peterson & Milt Jackson | Oscillation, The |
| Ose | OSH | Oshik Levy & Naftaly Alter |
| OSI | Osibisa | Osipov Academic Russian Folk O |
| Osiris | Oskar, Lee | Oslin, K.T. |
| Oslo Philharmonic Orchestra | Osmond Boys | Osmond, Donny |
| Osmond, Jimmy | Osmond, Marie | Osmonds, The |
| Osmosis | Ossian | Ossie & The Upsetters |
| Osterman Weekend, The | Ostrogoth | Osymyso |
| Otep | Other Half, The | Other Ones, The |
| Other People | Other Two, The | Othermothers, The |
| Others [1960S], The | Otherwise | Otis & The King Pins |
| Otis Johnny | Otis Williams And His Charms | Otis, Shuggie |
| Ottawan | Ottewell, Ben | Otway & Barrett |
| Otway John | Ou Est Le Swimming Pool | Oui 3 |
| Ouida & The Numbers | Ounsworth, Alec | Our American Cousins |
| Our Broken Garden | Our Daughters Wedding | Our Favourite Band |
| Our Future Feelings | Our Heaven | Our Kid |
| Our Lady Peace | Our Tribe | Ousset, Cécile |
| Out Of My Hair | Out Of The Blue | Out Of Your Mouth |
| Out With Mummy | Out, Papercut | Out-Phaze |
| Outcasts | Outcry Collective | Outer Limits, The |
| Outfield | Outhere Brothers, The | Outkast |
| Outlander | Outlandish | Outlaw Blues Band, The |
| Outlaws, The (UK) | Outlaws, The (US) | Outloud |
| Outnumbered, The | Outpatience, The | Outrider |
| Outside | Outsiders (Punk), The | Outsiders, The |
| Outsiders, The | Outsiders, The | Outsiders, The (US) |
| Outskirts Of Infinity | Outskirts, The | Ova |
| Ovary Lodge | Overdraft, The | Overkill |
| Overlanders, The | Overload, Honcho | Overlord |
| Overlords, The | Overmono | Overstreet, Tommy |
| Overtones, The | Owen | Owen And Leon |
| Owen, Mark | Owen, Michael | Owen, Ray |
| Owen, Reg | Owen, Sid & Patty Palmer | Owens, Buck |
| Owens, Frank | Owens, Jack | Owens, Jimmy |
| Owens, Robert | Owens, Tim 'Ripper' | Owens, Tony |
| Owl Service, The | Owls | Oxbow |
| Oxfam Glamour Models | Oxford Nights, The | Oxford, Vernon |
| Oxide Neutrino | Oxley, Louie | Oxley, Tony |
| OXO | Oxy And The Morons | Oxym |
| Oyster Band, The | Oysterband | Oysterhead |
| Oyuugi Wagamama Dan X PaRADEiS | OZ Magazine | Ozark Mountain Daredevils, The |
| Ozo | Ozomatli | Ozone |
| Ozone, Makoto | Ozric Tentacles | Ozzie Warlock And The Wizards |