| 501 | | Old Crow Medicine Show Featuring Gillian Welch & David Rawlings | |
| 502 | | Old Dead Tree | |
| 503 | | Old Dirty Bastard Aka Dirt McGirt And Black Keith | Hip-Hop |
| 504 | | Old Funeral | |
| 505 | | Old Kids On The Block | |
| 506 | | Old Lady Drivers | Hardcore |
| 507 | | Old Man Gloom | Hardcore/Metal |
| 508 | | Old Man Luedecke | Acoustic/Folk |
| 509 | | Old Man Markley | Country/Folk/Punk |
| 510 | | Old Man Rapper AKA Mr. Nat | |
| 511 | | Old Man River | Folk/Indie/Pop |
| 512 | | Old Mans Child | Metal |
| 513 | | Old Navy Players | |
| 514 | | OLD (O.L.D.) | |
| 515 | | Old Roger | |
| 516 | | Old Sand Mill | |
| 517 | | Old School Movie | |
| 518 | | Old School Players | |
| 519 | | Old Songs, Lullabies, Shanties etc. | |
| 520 | | Oldelaf & Mr D. | |
| 521 | | Oldfield Mike | |
| 522 | | Oldfield Sally | |
| 523 | | Oldies | |
| 524 | | Oldminion | |
| 525 | | Oldnfade | |
70s/80s/Country/Pop
Electronic/Hardcore
Rock
Emo/Hardcore