Osa
There are at least 2 solo musicians and one band who are known by the name OSA.
1) OSA (or Omid Sadeghi-Alavijeh) is a one man acoustic band. Having split form the small time punk rockers FAD, he went on to record a number of tunes form his home in North London. Having only been around for about 6 months he is a new musician on the scene with a small but loyal fanbase.
Check him out at www.myspca.com/omidsa
2) OSA, short for Osamede (meaning God crowns you) is an MC originally from the Bronx NY and currently located in Los Angeles CA.