By Ricky O’Bannon

It’s an ethereal, otherworldly sound that for classical concertgoers rings in the Christmas season and that is time again to wonder just “what the heck is a sugar plum fairy?”

But while the celesta is best known for its annual place in productions of Tchaikovsky’s The Nutcracker, the instrument has a significant if under-celebrated place in both classical music and early jazz.

Like other keyboard instruments, the celesta’s keys trigger hammers that strike metal plates suspended over wooden resonating blocks to produce tones. It’s easy to mistake the celesta as one of many early keyboard instruments like the harpsichord or clavichord that fell out of use against the rising popularity of the piano, but first invented in 1886 by a Parisian harmonium builder, the celesta is a relatively young instrument — even younger than the saxophone. Below is the famous celesta solo from The Nutcracker.

Jon Kalbfleisch has played his fair share of Nutcracker performances as a celesta player and regular fill-in on keyboard with the BSO. Kalbfleisch said that he has to take a much different approach when playing the celesta than playing piano.

“The celesta has a bell-like tone that’s limited in terms of dynamics and touch,” he said. “The piano can whisper or roar, but the celesta just sounds heavenly.”

That “heavenly” sound — which is where the celesta gets its name — is delicate and easily overwhelmed by orchestra instruments that have more dynamic gravitas. This means that when composers write for the celesta, they either write for the instrument alone with a few other voices or they allow the celesta sound to be obscured and employ it for a background special effect.

“If the celesta is meant to be heard, there won’t be much else going on in the orchestra,” Kalbfleisch said. “So you have to listen very carefully to who else is playing and breathe with them so that the sound of the celesta is part of the overall texture.”

Tchaikovsky was the first well-known composer to make serious use of the celesta in his symphonic poem The Voyevoda, one year prior to The Nutcracker. But the instrument has seen regular use by a number of prominent composers including Gustav Mahler in his sixth and eighth symphonies, Gustav Holst in the Neptune movement of The Planets, George Gershwin in An American in Paris, Ferde Grofé in Grand Canyon Suite and Béla Bartók in his Music for Strings, Percussion and Celesta.

In the 1920s, many jazz pianists dabbled with the celesta as an alternative instrument. Fats Waller famously played a piano with one hand and the celesta with another. Duke Ellington used celesta in several recordings, and later jazz pianists like Thelonius Monk played the celesta when bebop and cool jazz musicians were experimenting with different keyboard sounds like the vibraphone. In general, many of the jazz uses of celesta retained some of that celestial quality but often got a plunky more percussive sound from the instrument like in the introduction to Louis Armstrong’s Basin Street Blues.

The celesta has also found a home in movie scores, and perhaps the most famous celesta solo outside of Tchaikovsky is found in the main theme from John Williams’ Harry Potter score.

The celesta is just absolutely the perfect sound for creating that magical, fantastic environment,” celesta player Lura Johnson said of the Harry Potter theme.

Johnson is a keyboard player who regularly plays piano and celesta with the BSO and other orchestras. Going back and forth between the two instruments presents a different set of challenges, and Johnson said that she’s been told by other musicians it is hard to find a good celesta player.

Part of that challenge comes from the mechanical nuances of each. There is far less dynamic range in a celesta than piano, but Johnson said it is still possible to provide subtle volume changes, which can be the added musicianship that separates acceptable celesta players from the exceptional.

There is also a surprising contrast between the nimble, delicate sound of the instrument and the feel of playing a celesta, which Johnson said can seem sluggish when compared to the hyper-sensitive piano.

“Although the sound is immediate, I think the hammers have to travel further through space to get to their arrival point,” she said. “So there is a sense of walking through deep mud. You have to put your high boots on when you play the celesta.”

This December, Johnson will play celesta for more than a dozen performances of The Nutcracker in Baltimore, Delaware and Washington, D.C. Fortunately for her, Johnson said she doesn’t tire of playing the musical role of a sugar plum fairy.

“It's such a relief for us that the piece of music that everybody has decided to love and want to hear every year is such a beautifully written and enchanting piece,” she said. “We really dodged a bullet. It could have been bad.”