A lot of mnemonics are tunes.
Here's a bizarre one from French class:
This is to remember the verbs that take "etre" in the passe compose:
((To the tune of "Yankee Doodle", if you can believe it))
"aller, partir, sortir, venir,
devenir, retourner,
arriver, rester, entrer, monter,
tomber, naitre, mourir."
My French teacher was an actual Frenchman, not a nun.