O Total bands: 59

Wendy O Williams O-Town O-V-S-A O-Zone OAG Oak Ridge Boys OAR Oasis Oatmeal Dog Obituary Oblivion The Oc Supertones Ric Ocasek Occipitool Ocean Ocean Blue Ocean Colour Scene Ocean Eleven Ocean Hero Octavia Odd And Idle Odd Project Odds Odium Odorants Off By One Offbeatz Officer Negative Chris Offill Offspring Oil Old Mans Child Will Oldham Oleander OMC One Minute Silence OneSideZero Operation Ivy OPM Opthalamia Orange And Lemons Orange Goblin Roy Orbison Ordinary Boys Orgy Tony Orlando Orphaned Land Orson Joan Osborne Kelly Osbourne Ozzy Osbourne Osker Oslo Motherfuckers Otep The Others Our Lady Peace Overkill Chris Owen Ozma