From the brains behind brains on, this is the Moment of Um.

Moment of Um comes to you from APM Studios. I'm Mixmaster Macy.

Um, I'm a part-time DJ and a full-time beat fanatic.

I also run a very successful tax preparation service for small businesses, but that's just my day job.

When I'm not doing that, I'm looking for fresh new beats.

Like the other day, I heard someone slurping up soup with a silver spoon.

I thought to myself, Maisie, that's a groovy beat.

So I recorded it and turned it into this.

Oh yeah, Mix Master Maisie strikes again.

One of my tax clients also happens to be my doctor, and the other day I was getting a

checkup, and she said she needed to listen to my heartbeat. She also asked if she could still apply for an

electric vehicle tax break if she bought used. But mostly, we talked about my sweet, sweet heartbeat.

I thought to myself, Maisie, that's a beat you need to hear. But Doc said I would need a stethoscope.

What is a stethoscope anyway? And how does it work? Leona must be hunting for boss beats from the body,

too, because they asked, how does a stethoscope work? I bet a doctor can answer this one.

So a doctor can answer this one. So a doctor or a nurse uses a stethoscope to listen.

My name is Emma Girsten-Zang, and I'm a pediatrician in Philadelphia.

They use it to listen to your lungs, to your heart, to your belly,

and see if anything sounds funny and makes, you know, a doctor or nurse think that you might be sick.

How a stethoscope works is it allows sound to travel up a tube filled with air.

You press it up against someone's chest, and then that amplifies the sound, makes the sound louder,

and then the sound, which is basically just a vibration and air, travels up that rubber tube.

...