There's always more that can be said but I think I got at what you're asking in a response to a previous question:

But regarding songs, they were a common tool long before the familiar one you mention as children would sing the letters to the tune of a song they already knew. A popular one was the hymn "Refreshed by Gentle Slumbers" (which sounds similar to "My Bonnie Lies Over the Ocean"). There was also a rhyme/song called "Apple Pie ABC" or even more delightfully known as "The Tragical Death of A, Apple Pye Who was Cut in Pieces and Eat by Twenty-Five Gentlemen with whom All Little People Ought to be Very well acquainted."

The notes to "Gentle Slumbers" can be found here and the "Apple Pie ABC" lyrics can be found here.