Table: dance_central_songs
Columns: song_title
artist
decade
choreographer
rating
difficulty_out_of_7
character
dc2_character
dc3_venue
crew

Question: List all artists with choreographer Marcos Aguirre and a simple rating.
SQL: SELECT "artist" FROM dance_central_songs WHERE "choreographer" = 'Marcos Aguirre' AND "rating" = 'Simple'