The Sugar Plum Fairy's celesta hides metal behind its keyboard

The keyboard looks like a piano's. Inside a celesta, however, hammers strike metal bars with a wooden resonating box beneath each one. That construction gives the celesta its soft, metallic colour, the one heard in the Sugar Plum Fairy's dance in Tchaikovsky's The Nutcracker.

Yamaha's instrument guide says a celesta is played like a piano, but the pedal needs skill to bring out its characteristic reverberation. Listen beyond the arrival of each note: what lingers helps determine how the next one will be heard.

Tchaikovsky wanted to keep this colour to himself for a while. In an 1891 letter he thanked his publisher Pyotr Jurgenson for ordering a Mustel celesta and asked that no one else hear it before the first performance of the piece in which it would debut. If it reached Moscow first, Jurgenson was to “protect it from outsiders”. He also said it would play a large role in his new ballet.

The Nutcracker was not his first work to use it: the symphonic ballad The Voyevoda came earlier. Fame and first use are different milestones. The accompanying Royal Ballet clip offers a way to match the instrument to the dance: a sound once kept under guard now announces the scene.