Very simple and very fun!
All you need is the book: Mortimer by Robert Munsch and...
Every time Mortimer sings "Clang, clang. Rattle, bing bang. Gonna make my noise all day", the children make noise with the instruments! I have done the story with the kids making loud noises with the instruments, medium-level noises, soft noises and even as-quiet-as-a-mouse noises. It's a ton of fun!! (Though, I do recommend you close the door during this circle time story!)