Question: What instrument did the musician with last name "Heilo" use in the song "Le Pop"?
SQL: SELECT T4.instrument FROM Performance AS T1 JOIN Band AS T2 ON T1.bandmate = T2.id JOIN Songs AS T3 ON T3.SongId = T1.SongId JOIN Instruments AS T4 ON T4.songid = T3.songid AND T4.bandmateid = T2.id WHERE T2.lastname = "Heilo" AND T3.title = "Le Pop"