> The exact way of accomplishing this is left as an exercise

Perhaps you should undertake this exercise and let us know how it sounds :)

EDIT: In my experience with audio, when I have a bug that introduces even the slightest discontinuity (or even just a cusp) in the audio, well short of a pop to silence, I can still hear a "weirdness". Ears are pretty attuned to things that sound unnatural. I'm not confident that essentially "forging" the audio is going to sound natural.

What if you train a deep neural network on the song so far, so it can generate plausible-sounding music whenever the buffer drops?

You can even hang intentionally to generate original music!

(/s, please don't)

As another comment mentioned, this is done by conferencing software to deal with packet loss. It sounds like they either loop the previous DCT frame and gradually fade out, or feed the time domain output into a reverb, then cross-fade from 100% dry to 100% wet if the buffer is about to run out (someone on HN mentioned a while back that this approach was patented).

You could maybe make an argument that it would be useful in live music settings to prevent a bad situation from sounding even worse, and maybe you'd put it on some audio software so you can sort of still enjoy playing music on a crappy system, but really, it's best to have hardware and software that can 100% guarantee keeping up with audio processing.

I like the idea but one problem is that you usually encounter a buffer underrun when the cpu can't keep up, and so adding an extra step would require something like leaving enough processing headroom each buffer to halt it early and run the approximater.

edited typo