To put a nice finish on the game and give them an introduction to the musical alphabet, sing the ABC Alphabet Song to the tune of "Twinkle Twinkle Little Star", pointing to the cards as you sing.
Point a bit ahead to the A each time to help them sing "A" rather than singing " H I J". If most everyone carries on with "H I J" it's okay to joke, "H? Where's the H? Ummm. We're singing the musical alphabet and we only have these letters. Let's try again from the beginning." If someone tries to get attention and control by singing "H I J . . ", it’s usually best to ignore this and carry on through the song. Six sets of alphabet cards will exactly match the song.