I must say that I also use All Cows Eat Grass, ect., as I too learned this way, but I also have my beginning students sing the notes on some of their really easy songs--C, D, C, D, C2, C2, C, D, C, D C234. The numbers indicate half and whole note values. I don't do this for every song, but for example, I have a young boy starting his second book, and the first 8 songs are a review of the first book, so I've asked him to sing them, since just playing them would be a piece of cake. Just a thought.