Tchaikovsky's belief in the purity of ballet as well as its link to childhood lies at the core of his intent in and approach to composing ballet music. According to friend and music critic Herman Laroche, the composer welcomed writing for the ballet because, “in that magical world, it was pure fairy tale expressed by pantomime and dance”. Laroche added, “Tchaikovsky could not stand realism in ballet.” Tchaikovsky reserved ballet as the ideal genre for complete submersion into a child's fantasy world and so his Swan Lake, The Sleeping Beauty and The Nutcracker are all fantastic tales that draw the audience into a magical world of swan maidens, sorcerers, fairies, mouse kings, princes and princesses. In this chapter, I will show how Tchaikovsky's music for these ballets is the key that unlocks the door to a fairy-tale world. For pantomime and dance, the visual tools used to convey these stories cannot alone evoke the fantasy. It is Tchaikovsky's music, especially in his masterful choice of instruments and ways of deploying them, that transports his audience to a world of fantasy and magic.