How does a music box work?
A music box has no speaker, no battery and no recording. Its sound comes from a tiny steel comb plucked by a turning drum of pins, the same idea Swiss watchmakers perfected more than two centuries ago.
The four parts of a music box movement
The working heart of a music box is called the movement. Almost every traditional movement, from a ballerina jewellery box to a musical toy, is built from the same four parts.
- The comb
- A flat strip of hardened steel cut into a row of thin teeth, like a comb. Each tooth is a different length and is tuned to a single note: long teeth ring low, short teeth ring high. Small music boxes usually have around 18 teeth; larger movements have many more.
- The cylinder
- A small brass drum studded with tiny pins. As it turns, each pin catches a tooth of the comb, lifts it and lets it go, and the tooth rings. Where the pins sit around the drum decides the order of the notes, and the spacing between them decides the rhythm. The tune is literally written in pins.
- The drive
- Something has to turn the cylinder. Most music boxes use a coiled spring that you wind with a key. Hand-crank movements skip the spring and play while you turn a small handle, following the speed you turn it.
- The governor
- Spring-driven movements include a tiny spinning fan, or air brake, that pushes against the air and stops the spring from racing. It keeps the tempo steady from the first note to the last.
From pins to a melody
When the cylinder turns, the pins pass the comb one after another. Each pin bends its tooth for a moment and then releases it, and the tooth vibrates at its tuned pitch. Because the comb is steel, the note rings on after it is plucked, which gives music boxes their bright, bell-like sparkle.
Arranging a tune for a music box is a craft of its own. The arranger has to fit the melody onto the notes the comb can play, decide which harmony notes to keep, and space everything so the tune sounds right at the speed the cylinder turns.
A very short history
The comb-and-cylinder music box is usually traced to Antoine Favre, a Geneva watchmaker who described a way of making music with tuned steel teeth in 1796. Switzerland, and the Jura village of Sainte-Croix in particular, became the centre of music box making through the 1800s.
By the late 19th century, disc music boxes with interchangeable metal discs were popular parlour entertainment, until the phonograph took their place. The small cylinder movement survived and found its lasting home in jewellery boxes, musical toys and keepsakes.
How the Musical Drawer uses the same idea
The Musical Drawer is a tiny, self-contained music box movement that fits entirely inside a drawer you already own. The housed movement is secured to the fixed inner frame of the cabinet. A slim toothed rail along the inner side of the drawer moves with it and turns the movement’s enclosed crank input, so opening the drawer is what plays the tune.
It is still in development: final dimensions, fit and installation details are being finalised, and the illustrations on this site are concepts. See how it works on the home page or browse the tunes.
Music box questions
Why does a music box tune only last a few seconds?
On most small movements, one turn of the cylinder is one complete play of the tune. A small cylinder only has room for a short melody, often well under half a minute, before it loops back to the start.
Why do some music boxes sound richer than others?
More teeth means more notes and more room for harmony, and a larger, heavier comb rings for longer. The box itself matters too: a wooden case acts like a little sounding board and makes the sound fuller.
Can a music box play any song?
Only if the melody fits the comb. Every note in the arrangement needs a tooth tuned to it, so songs with a very wide range or fast, dense passages need to be simplified. That is why custom tunes are arranged individually.