I had a day in the past two weeks after lunch where about half of my 5th grade class was lunch working and about 5 others were sick that day. We only had about 10 total kids, so we just played games. One of the kids suggested we play “corners”, so we adapted it to music. The counter would sing the numbers, but you could also have each corner be a musical term or a rhythm, instead of just a number. They had fun. Here is a post about the game corners:
Corners