Book 3 introduces the concepts of key, key signature, scales, triads, tones, and semitones in a novel and exciting way: each key is a group of characters or objects with note-names (i.e. a band, a birthday party, a clothes-line with garments). Certain notes belong, while all other notes (accidentals) are outsiders. Transposition is a natural outcome of this concept, with a tune moving from one group to another. The child masters eight new notes (up to Treble High G and down to Bass Low F), which facilitates the playing of a more adventurous repertoire The semiquaver, semiquaver rest, dotted crotchet, and dotted quaver are introduced, and tempo markings are now in Italian. As in the previous two books, ensemble-playing is encouraged.