Database: music_2
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"