Title: The little orchestra series
Description: A lovely book to help infant teachers (KS 1) to introduce musical composition. Each character has a suggested instrument and they can decide how to play it when the character comes into the story - choosing duration, dynamics etc (if you want to stick to the NC music!). What a pity there wasn't a series 2 as far as I know. I bought a few of them when my local music shop closed down and I now use them in in-service support to teachers.
There are three stories in the book, and then they can progress to choosing their own instruments (timbre) for other stories and poems, or choosing different instruments for these stories to improve on their first try. 
This book isn't in print any more, but maybe if enough people complain to the publishers, they may release it again. You may find some secondhand if you're very lucky.
Subjects: music, composition, class music, instruments, key stage 1, infants, teaching music