There are 2 O's:

1. O is a Finnish black metal band formed in 2000 in Pietarsaari, Finland. O is signed with Woodcut Records.

Style-wise, the band changed from raw blackmetal to somewhat more industrial influenced blackmetal using samples and electronic effects. This makes the musical style somewhat similar to ...And Oceans or their later incarnation Havoc Unit. O also features members from ...And Oceans.

Current-Line-up:
- Petri Seikkula (...And Oceans)
- Deathbound (ex-The True Black Dawn)
- Sami Latva (...And Oceans, Deathbound, Ghost Guard, Rotten Sound)

Albums:
O/Flauros (2000) Split CD: O, Flauros
O (2004), EP
O.B.C (2005) Split CD: O, Black Dawn, Enochian Crescent

Official websites:
O at MySpace: http://www.myspace.com/otheband1
O at Woodcut Records: http://www.woodcutrecords.com/o.html

2. O is the moniker of Mika Vainio - member of Pan Sonic. O cross-hatches between shades of the original Pan Sonic heavy industrial sound, with the more delicate tones of his explorative ambience heard on the fabulous ‘Kantamoinen’ album, in classic Vainio style, marrying the two and birthing a perfect balance of Teutonic techno darkness and seasoned Finnish solitude from his base in Berlin.