Introducing the Cards
Holding up the cover card, point to the right edge of the card to show the students that there is no bar line. "In printed music, there is no bar line after this important information showing the clef, key signature, and time signature, so there is no bar line on this card either." Point to each component as you say, "This score of 'Daily Do' is in the treble clef, the key signature is C Major, and the time signature is in cut time or 2/2."
"You'll notice that each card has a bar line on either the right or left side except for the first measure, right? Can you find the first song puzzle card? Let's sing and sign this together."
Some students will jump right in and practically write the song without needing much more of your guidance. As needed, invite the students to join you as you sing together from the beginning card.
Stay close by and remain respectfully quiet in the background to give the students space to concentrate, work cooperatively within the group, and sing the song together as each card is added.
When finished, point to the cards, singing "Daily Do" together, with or without hand signs.
The cards can be pushed together to clean up.
Or you can play Dictation Cleanup. You and/or the students take turns singing and signing one measure for everyone else to find, putting each card in turn in a stack.