Obrecht, Jacob
Ockeghem, Johannes
Offenbach, Jacques
Okamoto, Shinsuke
Ónozó János
Orbán György
Oromszegi Ottó
Országh Tivadar
Ortiz, Diego
Ott Rezső
Ónozó János (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)
Ormay Imre (translated by)
Ormay Imre (words by)
Oromszegi Ottó (edited by)
Országh Tivadar (transcribed by)
Országh Tivadar (transcribed for violin and piano)
Országh Tivadar (compiled by)
Ortega, J. (edited by)
Ortega, J. (transcribed and edited by)
Osvát Erzsébet (words by)
Ott Rezső (piano score by)