This is a very infuential video. I often see it referenced when digital audio gets explained.

It is also very insiduously misleading in a way that is hard to fault it for.

That "band limited signal" that uniquely satisfies Niquist theorem? That is an infinite, periodic signal.

No finite (e. g. a song), aperiodic signal can be band limited. That includes any signal with transients.

Well, how big is the difference? How much overhead/error/lookahead is needed to approach the Niquist result? It is never mentioned by people referring to this theorem when talking about audio signal sampling!

And I wish it was mentioned and explained.

I think the constraint of using a band limited signal is the big misunderstanding many people have in regards to digital audio.

Yes, you can perfectly reproduce a band limited signal as long as the highest frequency is below fs/2.

But to get a band limited signal from a “real life” signal without any artifacts can be trickier than one might think. Especially when the Nyquist frequency is near the limit of human hearing.

And this is the one big argument in favor of Hi Res audio - moving those filter frequencies high above the hearing threshold.