Another example of a "Qui, Quae, Quod" mnemonic song:

Qui, Quae, Quod,
Qui, Quae, Quae,
Cuius, Cuius, Cuius
Quorum, Quarum, Quorum
First there's Cui and then there's Quibus
Quem, Quam, Quod and Quos, Quas, Quae
Quo, Qua, Quo and then there's Quibus
 Now we're done

Retrieved from here: http://sbeclatin.weebly.com/uploads/1/9/4/3/19430877/relative_pronouns.rtf

There are other mnemonic "Qui, Quae, Quod" songs on Youtube.

Perhaps this "nonsense" song is nothing but a Latin language teaching song.