| Abbreviation | Definition |
|---|---|
| OG | Oldies Guru |
| OG | Original Guild |
| OGB | Old Goats Band |
| OGG | Official Ghetto Girls |
| OGOD | Ocean Gang Or Drown |
| OHD | Oh Hey Doctor |
| OHIO | Our Hand Is Out |
| OHJ | Our Hero`s Journey |
| OHM | Only House Music |
| OHMS | Ohio Hystairical Musick Society |
| OHSC | Official HardShell Case |
| OHWM | Oxford History of Western Music |
| OI | Opportunistic Infections |
| OIFD | Omaha International Folk Dancers |
| OIG | Overall Instrumental Guidance |
| OIHB | Oklahoma Intercollegiate Honor Band |
| OIMA | Ontario Independent Music Archive |
| OJC | Original Jazz Classics |
| OJD | Orange Juice Discography |
| OJE | Oberlin Jazz Ensemble |