Unaccompanied or A cappella styles of singing are performed across the modern Celtic world due to the folk music revival, popularity of Celtic choirs, world music, scat singing and hip hop rapping in Celtic languages. Traditional rhythmic styles used to accompany dancing and now performed are Puirt a beul from Scotland, Ireland, and Cape Breton Island, Nova Scotia, Sean-nós song from Ireland and Kan ha diskan from Brittany. Other traditional unaccompanied styles sung currently are Waulking song and Psalm singing or Lining out both from Scotland.