Releases
 | Operaar Poephaar (2019) kindermuziek De Piepkes |
 | Operation: Citadel (1999) hardrock / metal / hardcore In-Quest |
|---|---|---|---|
 | Opex (2022) Rock / Alternative Arno |
 | Opgenomen verantwoordelijkheden (2015) improvisatie / experimenteel Vom Grill |
 | Ophelia - Songs of exile (2019) Klassiek Clara Inglese |
 | Optie adoratie (2001) kleinkunst Sabien Tiels |
 | Optimists (2014) electronica Mittland och Leo |
 | Opus #1 (2018) Jazz Matthias Van den Brande |
| Opéra de Wallonie II (1973) romantiek, opera Bedřich Smetana, Marcel Desiron, l'Orchestre de l'Opéra de Wallonie, Robert Bleser, Guy Fontagnère, Charles Gounod, Roger Rossel, Andrée François, Georges Bizet, Edith Tremblay, Reynaldo Hahn, Sabine Louis, Giuseppe Verdi, Giacomo Puccini, Jean Segani, Hector Berlioz, Annie Frantz, Louis Varney, Armand Battel, Jacques Legrand, Jules Massenet, José Razador, Mady Urbain |
 | Orange Moon (2020) Jazz Orange Moon |
 | Orange for tea (2004) Jazz Tricycle |
 | Orations at the keyboard (2001) classicisme Tom Beghin, Joseph Haydn |
| Oratorio Ishango (2003) Chris Joris, Daniel Schell, Fabrice Alleman, Chris Mentens, Chris Joris, Daniel Schell, Choeur Symphonique De Namur, Denis Menier |
 | Oratorium Rwanda (1998) 20ste eeuw Jan Caals, Werner van Mechelen, Catherine Vandevelde, Marianne Vliegen, Geert Van Der Straeten, Paul Dinneweth |
 | Orazio Vecchi: Requiem (2017) religieuze muziek Graindelavoix, Orazio Vecchi, Björn Schmelzer, George de La Hèle, Pedro Rimonte, Duarte Lobo, Paolo Bravusi |
| Orbisongs (2005) pop Bandit |
 | Orchestra Nazionale Della Luna (2017) Jazz Orchestra Nazionale Della Luna |
 | Orchestral Music I (2001) 20ste eeuw Vlaams Radiokoor (VRK), Vlaams Radio Orkest, Flor Alpaerts, Norbert Rosseau, Peter Benoit, Victor Legley, Arthur Meulemans, Edgar Tinel, Jan Latham-koenig |
 | Orchestral Music II (2002) 20ste eeuw Vlaams Radio Orkest, Michel Brusselmans, Flor Alpaerts, Lodewijk Mortelmans, Renaat Veremans, Frank Van der Stucken, Bjarte Engeset |
 | Orchestral Works 1 (2019) klassiek crossover Michelino Bisceglia |