Complex sentence: In August 2011, Omar Souleyman appeared at Paredes de Coura in Caribou to perform at the ATP Nightmare Before Christmas festival that they co-curated in December 2011 in Minehead, England.
Split into simpler sentences: In August 2011, Omar Souleyman appeared at Paredes de Coura in Portugal. Souleyman was chosen by Caribou to perform at the ATP Nightmare Before Christmas festival that they co-curated in December 2011 in Minehead, England.