You're listening to 20,000 Hertz. I'm Dallas Taylor.

Even those of us who know next to nothing about the music industry probably have some idea what

mixing is. For instance, we all know mixing involves some sort of leveling, like how loud or

quiet you want something to be. It also involves panning, whether you want an instrument or vocal part to be on the left or on

the right or somewhere in the middle.

And while you might use some effects while recording, a lot of other effects get added during

the mixing phase.

Maybe you want to add some reverb to the vocals, double track to give it a little more oomph.

Oh, auto tune those sweet vocals.

While working on a song, a mixing engineer will make a ton of decisions like these, both big and small.

But after being mixed, songs go through a whole other process before they get released.

This stage is much harder to explain, and while it's definitely more subtle than mixing,

it still ends up having a huge impact on the final sound.

This process is called mastering, and even inside the music industry, it's considered

something of a dark art, something that only a small group of elite specialists know how to do.

Mastering is the final step in making a commercial recording. That's Greg Milner. He's written about music and technology for publications like Slate, Wired, Rolling Stone, and the New York Times.

It's taking the fully mixed recording and essentially making it absolutely pristine and correct

to actually make it into something that people will listen to or buy.

In the old days, before digital technology, the mastering engineer was the person who would

literally make the physical master from what the recordings would be stamped from.

Back in the day, that would have been a vinyl master, then cassette, then CD, and these days

for digital files.

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