QUERY:SELECT DISTINCT charts.id_song FROM song_genre,song,main_chart,charts WHERE main_chart.id_program=9 AND main_chart.id_mainchart=charts.id_mainchart and charts.id_song=song.id_song and main_chart.frecuency='w' AND charts.best<=10 and song_genre.id_song=charts.id_song AND song_genre.id_genre=16 ORDER BY charts.id_song DESC