Which tracks are not in the music playlist?
SELECT T1.name FROM tracks AS T1 JOIN playlist_tracks AS T2 ON T1.id   =   T2.track_id JOIN playlists AS T3 ON T2.playlist_id   =   T3.id WHERE T3.name  ! =   'Music'
tracks not in the music playlist refers to selecting tracks where the playlist name is not equal to 'Music'; joining tracks with playlist_tracks and playlists to filter out tracks not included in the specified playlist;