Strike Up the (Marching) Band!
Gather instruments, such as maracas, tambourines, rhythm sticks, or bongos. Pick one of each and start playing while marching around the house. This is a great idea for when you have a few kids over for a playgroup. Don't have musical instruments? Make your own with dry beans in a yogurt container, coffee cans as drums, and tin pie plates as cymbals.