One of the best choices I ever made for my health was prioritizing regular checkups,

because when it comes to health, knowledge is power.

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That's Z-O-C-D-O-C.com slash H-E-R-T-Z.

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You're listening to 20,000 Hertz.

What you're hearing right now is one person's voice, layered in perfect harmony with itself,

using an instrument called a vocal harmonizer.

This is a live performance that hasn't been

edited or altered in any way. The voice itself isn't being digitally tuned, meaning one wrong

note and the harmonic structure will fall apart. The singer is Jacob Collier. So what happens when

I play the harmonizer is I sing a note and I play a few notes on the keyboard.

And what you hear coming out of the instrument is all of the notes I'm playing on the keyboard

sung by my voice. So it's almost like I can be this spontaneous choir.

Singers have used vocal harmonizers for a long time, but this one is special.

It was invented by Jacob, and he's one of the only people in the world who can make it sound

like this.

What I realized about this instrument, when I started to try and get my friends to try and play it,

is that it's really, really difficult to play unless you know what note you're singing.

Because if you know what note you're singing, like, say for example, I sing an E, or if I think,

oh, I want to play a chord of E major, and I go, ooh, and I play the chord, I don't have to think about trying to find

...