This book is an interpretation of an old Italian song for children about a blackbird who loses his beak, and was designed based on a concept that Munari first developed in 1940. In this creative children's book, Various parts of a blackbird are printed on transparent sheets of PVC plastic, so that in the beginning, the entire blackbird is visible. First, the poor blackbird loses its beak as the page is turned, and then its eye, wing, and leg, and so on, until all that is left is its heart. Below the illustration is the text of each verse of the song, and the chorus. Bound in flexible black plastic covers with a design of blackbirds on musical staves on the front, and the music to the song on the back, printed in white.