I have long wondered why "Alphabetic Order" is the order that it is, and have failed to find the answer beyond:

"It evolved from the order assigned by the Ancient Greeks, and was later adapted by the Romans."

...But I've found no reason behind Alpha being first and Omega last, et cetera (alas!).

So -- since that knowledge seems to be lost to the mists of time, perhaps some kind soul can tell me why "Twinkle, Twinkle, Little Star" (aka "The Star," aka "Ah! Vous Dirai-Je, Maman") is now taken as the tune for the alphabet.

What tune, if any, did children use as a mnemonic before this melody was composed?