| Ó Riada, Seán | Klein, Axel |
| O‘Dwyer, Robert | Klein, Axel |
| O‘Keefe, John | Boydell, Barra |
| O‘Leary, Jane | Klein, Axel |
| O’Hara, Kane | Boydell,Brian Klein, Axel |
| Oberlender | Lücke, Martin |
| Oberlinger, Familie | Rodeland, Jürgen |
| Obiols Tramullas, Mariano | Cortès, Francesc |
| Oboussier, Robert | Baumgartner, Michael |
| Obrecht, Jacob | Finscher, Ludwig |
| Obuchov, Nikolaj | Gojowy, Detlef |
| Ocenas, Andrej | Bardiova, Marianna |
| Ochman, Wieslaw | Luther, Einhard |
| Ochs, Phil | Wicke, Peter |
| Ochs, Siegfried | Oechsle, Siegfried |
| Ochsenkun, Sebastian | Meyer, Christan |
| Ockeghem, Johannes de | Fallows, David |
| Odak, Krsto | Blazekovic, Zdravko |
| Odette, Paul | Bork, Detlev; Jewanski, Jörg |
| Odington, Walter | Hentschel, Frank |
| Odoevskij, Vladimir | Petrov, Daniil |
| Odorannus von Sens | Gümpel, Karl-Werner |
| Oechsle, Siegfried | Oechsle, Siegfried |
| Oehring, Helmut | Thein, Annette |
| Oesch, Hans | Mosch, Ulrich |
| Oestreich, Familie | Rehm, Gottfried |
| Oettingen, Arthur Joachim von | Reuter, Christoph |
| Ofenbauer, Christian | Weidringer, Walter |
| Offenbach, Jacques (Biographie) | Jahrmärker, Manuela |
| Offenbach, Jacques (Editionen und Fassungen) | Krause, Andreas |
| Offenbach, Jacques (Würdigung) | Hofer, Hermann |
| Öglin, Erhard | Lodes, Birgit |
| Ohana, Maurice | Tual, François-Gildas |
| Ohnewald, Joseph | Ullrich, Hermann |
| Ojstrach, Familie | Eichhorn, Friedemann |
| Olah, Tiberiu | Tomescu, Vasile |
| Oldovini | Janeiro, João Paulo |
| Oldovini, Pascoal Caetano | Doderer, Gerhard |
| Olenin, Familie | Purtov, Feliks |
| Oley, Johann Christoph | Timm-Hartmann, Cordula |
| Oliba von Ripoll | Gümpel, Karl-Werner |
| Oliveira, Jamary | Béhague, Gerard |
| Oliveira, João Pedro | Cascudo, Teresa |
| Oliveira, Jocy de | Béhague, Gerard |
| Oliveira, Willy Correia de | Béhague, Gerard |
| Oliver | Lefferts, Peter M. |
| Oliver Pina, Ángel | Heine, Christiana |
| Oliver, Joe | Kolleritsch, Elisabeth |
| Olivero, Betty | Hirshberg, Jehoash |
| Olivero, Magda | Blyth-Schofield, Susan |
| Oliveros, Pauline | Feisst, Sabine M. |
| Olivier | Stone, Anne |
| Olmeda (de San José), Federico | Nommick, Yvan |
| Olsen, Ole | Herresthal, Harald |
| Olsen, Poul Rovsing | Waskowska, Teresa |
| Olsen, Sparre | Herresthal, Harald |
| Olsson, Otto Emanuel | Andersson, Greger |
| Olthof, Statius | Waczkat, Andreas |
| Ondricek, Frantisek | Kachlik, Jan |
| Onegin, Sigrid | Büchl, Alois |
| Onslow, Georges | Nobach, Christiana |
| Oosterzee, Cornelie van | Metzelaar, Helen |
| Op de Coul, Paul | Op de Coul, Paul |
| Opilionis, Othmas | Schmid, Bernhold |
| Opitiis, Benedictus de | Schmidt-Beste, Thomas |
| Opitz, Martin | Rothmund, Elisabeth |
| Oppitz, Gerhard | Eichhorn, Friedemann |
| Oppo, Franco | Mattietti, Gianluigi |
| Oramo, Ilkka | Oramo, Ilkka |
| Orbón, Julión | Eli Rodríguez, Victoria |
| Orchestra of the 18th Century | Nasir, Saad |
| Orchestra of the Age of Enlightenment | Elste, Martin |
| Ordonez, Carlo d' | Glüxam, Dagmar |
| Ore, Cecilie | Herresthal, Harald |
| Orefice, Antonio | Krause, Ralf |
| Orefice, Giacomo | König, Stefan |
| Orejón y Aparicio, José | León, Javier F. |
| Oresme, Nicolaus | Haas, Max |
| Orff, Carl | Rösch, Thomas |
| Orgad, Ben-Zion | Hirshberg, Jehoash |
| Orgeni, Aglaja | Büchl, Alois |
| Orgitano, Familie | Dietz, Hanns-Bertold |
| Oridryus, Johannes | Federhofer-Königs, Renate |
| Original Dixieland Jazz Band | Kolleritsch, Elisabeth |
| Oriola, Pietro | Urchueguía, Cristina |
| Oristagno, Giulio | Rossi, Francesco R. |
| Orjonikije, Givi | Cqonia, Sofia |
| Orlandi, Sante | Filippi, Daniele V. |
| Orlandini, Giuseppe Maria | Romagnoli, Angela |
| Orlando, Ferdinando | Aversano, Luca |
| Ormandy, Eugene | Behrens, Wolfgang |
| Ornitoparchus, Andreas | Loesch, Heinz von |
| Ornstein, Leo | Saffle, Michael |
| Orologio, Alessandro | Panagl, Victoria |
| Orpheus Chamber Orchestra | Elste, Martin |
| Orr, Robin Kemsley | Dunnett, Roderic |
| Orrego-Salas, Juan | Merino, Luis |
| Ørsted Pedersen, Niels-Henning | Straka, Manfred |
| Ortega del Villar, Ancieto | Miranda-Pérez, Ricardo |
| Ortells, Antonio Teodoro | Bruach, Agustí |
| Orthel, Leon | Wennekes, Emile |
| Ortigue, Joseph(-Louis) d' | Jahrmärker, Manuela |
| Ortiz, Diego | Griffiths, John |
| Ortiz-Fernández, Fernando | Moore, Robin |
| Orto, Marbrianus de | Pietschmann, Klaus |
| Ory, Edward | Messner, Wolfgang |
| Osborne, Nigel | Revill, David |
| Osculati, Giulio | Rossi, Francesco R. |
| Osiander, Lucas | Zywietz, Michael |
| Ossian | Schmidt, Wolf Gerhard |
| Osterc, Slavko | Blazekovic, Zdravko |
| Ostermaier, Andreas | Broszinski, Hartmut |
| Österreich, Georg | Lange, Carsten |
| Osthoff, Familie | Osthoff, Wolfgang |
| Ostrcil, Otakar | Kvasnicková, Petra |
| Oswald von Wolkenstein | Müller, Ulrich |
| Oswald, Henrique | Béhague, Gerard |
| Oswald, James | Harris, Moira A. |
| Otaño Eguino, Nemesio | Mallinson, Jane Gómez Rodríguez, José Antonio |
| Otescu, Ion Nonna | Tomescu, Vasile |
| Othmayr, Caspar | Wagner Oettinger, Rebecca |
| Otker von Regensburg | Sachs, Klaus-Jürgen |
| Ott, Hans | Lodes, Birgit |
| Ott, Laurentius Justinianus | Münster, Robert |
| Otte, Hans | Henck, Herbert |
| Ottenberg, Hans günther | Ottenberg, Hans Günter |
| Otter, Anne Sofie von | Seedorf, Thomas |
| Otter, Familie | Boisits, Barbara |
| Otto, Georg | Bettels, Christian |
| Otto, Stephan | Rothaug, Diana |
| Otto, Valerius | Märker, Michael |
| Ottoboni, Familie | Dubowy, Norbert |
| Oudrid, Cristóbal | Cortizo, María Encina |
| Ouvrard, René | Vendrix, Philippe |
| Ovcinnikov, Vjaceslav | Zara, Vasco Karpinskij, Igor' |
| Ovid | Draheim, Joachim |
| Owens, Jessie Ann | Owens, Jessie Ann |
| Ozawa, Seiji | Behrens, Wolfgang |
| Ozi, Etienne | Angerhöfer, Günther |