This was a simple activity I made up for a sub to use while I was in Utah, but I don't think she actually used it. But it could easily be adapted for any song.
I wrote each word to the song (in this case it was Beautiful Savior) on different colors of construction paper and taped them to a poster board. Show the poster and sing all the way through. Then have a child draw an object out of a grab bag (I used 5 different colored toy blocks). When you draw the yellow block, remove all the words that are on yellow paper and sing the song again. Depending on how many different colors of construction paper you choose to use, you will sing the song several times through, which is the whole point!