Table schema:
CREATE TABLE song (song_name VARCHAR, resolution INTEGER); CREATE TABLE song (song_name VARCHAR, f_id VARCHAR); CREATE TABLE files (f_id VARCHAR, formats VARCHAR)

Question: Return the names of songs for which format is mp3 and resolution is below 1000.
SQL: SELECT T2.song_name FROM files AS T1 JOIN song AS T2 ON T1.f_id = T2.f_id WHERE T1.formats = "mp3" INTERSECT SELECT song_name FROM song WHERE resolution < 1000