There are at least 4 artists with this name: 1st: SMA is a HipHop/Rap Crew from Essen, Germany. 2nd: SMA is a Ska/Rock band from Westfield, Massachusetts, mostly active in the 1990s. 3rd: there is also an amateur DJ guy playing house music and techno under the moniker sma. 4th:S.M.A. (Street Magic Art) is a HipHop/Rap Crew from Thessaloniki,Greece Check their official biography:
First and foremost S.M.A. is not just a band consisted of 2 MCs & 1 Dj, but far more than that they are a group of "friends", who represent Hip-Hop as a culture and as a movement the way they lived it.

Read more about SMA on Last.fm.