If there is no Lego Movie 3 it will resolve N/A.

By “song” it has to be a full song, not just a sentence that’s said in a voice that sounds like it’s from a song.

The song will have to mention somebody’s father dying, with a lyric like “your dad is dead” or something similar.

In an ambiguous case I will ask in a comment whether it should count, and if I am still unsure I will resolve at PROB.