I loved the song hospital idea I had read about (and will look up the source soon) and decided to adapt it a little bit for our primary. I dressed up as Dr. Sis. Larson and the primary room became a hospital.
In our waiting room each song was a patient and waited in a chair to be called back to the examining table.
Our examining table
While the song was on the table, the kids and I sang it and then assessed it using this chart. I had the older kids take turns filling it out themselves, and for the younger kids, I had them help with circling the numbers.
If the songs were healthy enough, they were discharged. Discharged songs were placed outside the door (as though they were going home). Songs that still needed some work were "admitted". I placed admitted songs on the board.