First, let me state that I believe that CD audio, played through a modern DAC and quality stereo equipment is pretty much the pinnacle of home audio listening. That is to say, I think 44.1kHz 16-bit PCM audio is plenty good and I'm in no rush to replace my CD collection, nor do I think significant investment in higher bandwidth audio (for playback, mixing and mastering are another story) buys you much.<p>That said, there's one thing the article does not address and that is "beating", or really inter-modulation distortion from instrumental overtones.<p>Instruments are not limited to 20-20kHz. They can have overtones well above this range. Additionally, note that short pulse-width signals, i.e. transients, like drum strikes, especially involving wooden percussion, can have infinite bandwidth. (Not really infinite, but pulse-width is inversely proportional to bandwidth.<p>In a real listening environment (i.e. live performance) these overtones have a chance to interact with one another in the air. It is possible that these overtones may beat with one another and cause inter-modulation products in the audible range. For an example of this, play a 1000 Hz tone through your left speaker, and a 1001 Hz through your right speaker. You will hear a distinct 1 Hz "beat". The audibility of these are largely dependent on listening position and amplitude, but it is possible to occur with instruments. Since most recordings are done using a "close mic" technique (placing the microphone very close to the source) the interactions such as this are never recorded.<p>However, if full bandwidth of the producing instruments is preserved, these interactions of the overtones can be reproduced in a playback environment given equipment having a wide enough bandwidth and degree of quality.