O'Brien, Richard O'Brien, Tim O'Callanain, Niall O'Carolan, Turlough O'Connell, Ryan O'Connor, Ella Yelich O'Donnell, Daniel O'Farrill, Chico O'Gorman, Peter O'Hara, Geoffrey O'Hara, Michael O'Keefe, Laurence O'Laoire, Lillis O'Leary, Jessica (editor) O'Mahoney, Terry O'Mara, Peter O'Neal, Barry O'Neill, Francis O'Neill, Jackie O'Neill, Paul O'Neill, Susan O'Regan, Tarik O'Reilly, John O'Reilly, Kim Oakland, Ben Oare, Michael OASIS Oberfeld, Casimir Oberst, Fritz Oberthur, Carl Obijalska, Dorota Obradors, Fernando Obrecht, Jacob Obrovska, Jana Obst, Michael Ocampo, Mauricio Cardozo Ochs, Siegfried Ockeghem, Johannes Ockelford, Adam Oddo, John Oddone, Edoardo Odeh-Tamimi, Samir Odeh-Tamini, Samir Odell, Tom Oden, Annette Odgren, Jim Odo, Franklin Odone, Alberto Oerding, Johannes Oermann, Nils Ole Offenbach, Jacques Ogiński, Michał Kleofas Ohana, Maurice Ohse, Reinhard Oja, Carol J. Okamoto, Shinsuke Okazaki, Miles Okoshi, Tiger Olah, Tiberiu Olatunji, Babatunde Olazabal, Tirso Oldenkamp, Michiel Oldham, Arthur Oldroyd, George Olias, Lotar Oliva, John Olivadoti, Joseph Oliver, Joseph King Oliver, Julian Oliver, Nancy Oliver, Sy Olivero, Betty Olivier, François Olivieri Sangiacomo, Elisa Oliviero, N. Olson, Lynn Freeman Olson, Robert Olson, Tawnie Olsson, Milton Olusola, Kevin Omar, Don Omartian, Michael Ondrasik, John Ondrícek, František Ondruš, Ján One Direction One Republic Ongarello, Antonio ónis Ono, Yoko Onovwerosuoke, Fred Ónozó János Onyeji, Christian Oosterhout, Arjen Oppo, Franco Oram, James Orbán György Orban, Marcel Orbison, Roy Orefice, Giacomo Orefici, Alberto Orff, Carl Oriol, Emmanuel Orkisz, Andrzej Orloff-Tschekorsky, Tatjana Orlowsky, David Orologio, Alessandro Oromszegi Ottó Orr, Buxton Orr, J. Orsi, Romeo Országh Tivadar Ort, Jirí Ortelli, Antonio Ortiz, Diego Ortiz, Suzzette Ortiz-Alvarado, Graciela Paraskevaídis William Ortolani, Riz Orton, Beth Osborn, Brad Osborne Osborne, Anthony Osborne, Nigel Osborne, Richard Osborne, Tony Osbourn, Leslie Osbourne, Ozzy Osentowski, Francis Osgood, Charles Oshrat, Kobi Osorio, Nuno Ospald, Klaus Osse, Klaus Ostendorf, Jens-Peter Osterling, Eric Ostleitner, Elena Ostransky, Leroy Ostrzyga, Michael Oswald, Albert Oswald, Gerald Otros, Y. Ott Rezső Ott, Daniel Ott, Eugen Ott, Karin Otte, Hans Otten, Mark Otterstedt, Annette Ouzounoff, Alexandre Ovadia, Moni Ovcharenko, Halyna Overduin, Jan Overthrow, David Ovokaitys, Cindy Owen, Barbara Owen, Randy Owen, Teodora Owen, William Owenby, Chris Owens, James T. Owens, Jessie Ann Owens, Jimmy Owens, Matthew Owens, Terry Winter Owens, Thomas Owsinsky, Bobby Oxa, Anna Ozi, Étienne Ozi, Etienne Ozim, Igor (Hrsg.) O'Loughlin, Sean (instrumentation by) O'Loughlin, Sean (arranged by) O'Neill, Jackie (arranged by) O'Neill, Norman (edited by) O'Regan, Noel (edited by) OASIS (author) Oberbek, Jan (edited by) Obst, Michael (arranged by) Obst, Michael (edited by) Ocean, Johny (instrumentation by) Ocker, Marshall (instrumentation by) Oddo, John (instrumentation by) Odermatt, Arnold (edited by) Oechsle, Siegfried (edited by) Oeser, Fritz (translated by) Oeser, Fritz (edited by) Oeser, Fritz (words by) Oeser, Fritz (transcribed by) Oesterle, Louis (edited by) Ofburg (instrumentation by) Offenbach, Jacques (composer) Ogonovsky, Margaret (arranged by) Ohanian, David (arranged by) Ohmen, Wilhelm (edited by) Ohmiya, Makoto (edited by) Oistrach, Igor (piano score by) Oldenkamp, Michiel (edited by) Oldman, Cecil B. (edited by) Oleskiewicz, Mary (edited by) Oliva, Petr (edited by) Ollivo, Yann (piano score by) Olson, Lynn Freeman (arranged by) Ondra, Jaroslav (arranged by) Ondrícek, František (transcribed by) Ongarello, Antonio (arranged by) Ónozó János (edited by) Opp, Walter (edited by) Oppermann, Annette (edited by) Orbán György (composer-contributor) Orbán György (edited by) Orbán György (arranged by) Orbán György (transcribed by) Orbán György (edited by) Orbán György (piano score by) Orbán Ottó (translated by) Orbaugh, William (arranged by) Orel, Alfred (edited by) Orel, Alfred (words by) Orenstein, Arbie (edited by) Orford, John (editor) (edited by) Orgelbuchkommission Baden, Elsaß, Lothringen und Pfalz (edited by) Ormay Imre (translated by) Ormay Imre (words by) Oromszegi Ottó (edited by) Orphee, Matanya (edited by) Országh Tivadar (transcribed by) Országh Tivadar (transcribed for violin and piano) Országh Tivadar (compiled by) Ortega, J. (transcribed and edited by) Ortega, J. (edited by) Ortiz, Juan (instrumentation by) Osborne, Tony (edited by) Osbourne, Ozzy (author) Ostendorf, Jens-Peter (edited by) Osterling, Eric (transcribed by) Osterling, Eric (instrumentation by) Osthoff, Helmuth (edited by) Osthoff, Wolfgang (edited by) Osvát Erzsébet (words by) Oswald, Gerald (instrumentation by) Ötsch, Barbara (edited by) Ott Rezső (piano score by) Otterstedt, Annette (edited by) Oud, Thijs (arranged by) Oud, Thijs (instrumentation by) Over, Bertold (edited by) Owen, Don (instrumentation by) Owen, Teodora (author) Ozawa, Kazuko (edited by) Ozim, Igor (edited by) Ozsvárt Viktória (edited by)