The price of a good idea

I've just spent a considerable portion of this evening cyphering Hen Wlad Fy Nhadau, La Marseillaise, Nessun Dorma, the Finlandia Hymn and Ein Feste Burg ist unser Gott for the purpose of having a "fun" cryptography investigation with my year 8's.

Here's hoping that after all that it actually works...