Tchaikovsky famously featured the celesta in The Nutcracker to imitate the sound of a magical toy.
The celesta is a keyboard instrument whose keys activate hammers that strike tuned metal plates. Its sound is light, bell-like, and unusually clear, making it effective for delicate or magical musical scenes.
Tchaikovsky encountered the instrument in Paris and arranged for it to be used secretly in The Nutcracker before its premiere in 1892. Its most famous appearance is the “Dance of the Sugar Plum Fairy.”
The celesta may resemble a small piano from the outside, but its sound-producing mechanism differs. A glockenspiel also uses metal bars, yet it is struck directly with mallets rather than operated by a keyboard.