The celesta is the keyboard instrument that produces sound by striking metal bars with small hammers.
A celesta resembles a small upright piano in appearance, but its tone comes from tuned metal plates or bars rather than ordinary piano strings. Pressing a key activates a felt-covered hammer, and the vibrating metal is amplified by wooden resonators or a cabinet.
The French instrument maker Auguste Mustel patented the celesta in 1886. The name comes from the French céleste, meaning “heavenly,” reflecting its delicate, bell-like sound. Celestas are usually played from a keyboard and are commonly treated as percussion instruments in orchestral scoring.
The instrument became especially famous in Tchaikovsky’s ballet The Nutcracker, where it creates the sparkling sound of the “Dance of the Sugar Plum Fairy.” It is sometimes mistaken for a glockenspiel because both use tuned metal, but a celesta has a keyboard and hammers, while a glockenspiel is normally struck directly with mallets.