From the brains behind brains on, this is the moment of um.

Moment of um comes to you from APM Studios. I'm Anna Goldfield.

When I was a kid, I had a music box that sat on top of my dresser. It was made of ceramic and was in the shape of a little grassy hill. On the hill there was a hedgehog in a dress and bonnet sitting in a swing that hung from a tree branch. I think it was supposed to be Mrs. Tiggy Winkle, a character from Beatrix Potter's children's stories. The base of the music box had a circular

metal dial on the bottom. If you wound up the dial and then put the music box right side up,

the whole thing would turn gently in circles while playing a tinkly little Mozart melody.

I couldn't see the insides of my music box, so I always wondered how it played its tune.

I like to imagine that there was a tiny xylophone player in there waiting for the chance to perform.

As cute as that is, I know it's not how my music box worked, so how do music boxes make music?

A listener also named Anna asked us this question too, so I found a music

box maker to tell me all about it. Music boxes are mechanical boxes that make music. I am Richard Uffchurch.

I am the owner-creator of brand-new noise.

I make creative sound gadgets and oddball instruments here in Dallas, Texas.

Let's think about how other instruments work.

The low notes on a piano or on a guitar, they're longer.

The strings are longer and wider.

If you look at a music box, most of them have this little hand crank, right?

That's the mechanical crank.

That's going to spin a cylinder, and it has little spikes on it, little nubs or spikes.

And what happens is as that turns, as you hand turn that cylinder, it's taking a piece of metal, longer or shorter, and plucking that piece of metal, just like on a

Columbia you do with your finger, but this is done with the mechanical roll or cylinder, and

that is going to make the sound of your music box.

It's fascinating when you look at it that someone had to figure out how to take a cylinder and put the notes in the right spot and the right distance apart.

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