Because Simon didn't understand how to communicate, the other children didn't understand him. This lack of understanding caused some children to tease him, and others to disregard him like the unwanted crusts of a sandwich.
When Simon stumbled into a music practice room his whole world changed. Who would have guessed the drum kit was magical? Becoming his friend and whisking him away to the land of Vozori, they encounter many strange and compelling creatures on their quest to find his voice.