At least 4 different bands / acts share this name: 1) Birthmark is Nate Kinsella of the Joan of Arc collective gone solo.
2) Birthmark is a rock band from Athens, Greece. Initially formed in 2001 under the name Cuore Nero.
3) A hardcore act from Banská Bystrica (Slovakia).
4) An experimental band from Brighton, East Sussex, England
1.) Under the appellation Birthmark, Nate Kinsella has embraced restraint in spite of the compositional boundlessness typically borne by musical virtuosity.

Read more about Birthmark on Last.fm.