Smooth treble

"live music sounds much more "smooth" and airy in the high frequency department."

Depends on where you are sitting relative to the source.

Sit next to a drum set and give the crash symbol a good whack. Chances are it is not so light and airy.

Mapman, yes it is very direct with high energy content (not very good for da ears), nevertheless it sounds very rich with rich overtones and also... airy. You can also hear there is some warmth (paradoxically) in this loud, aggressive and metallic sound of the cymbals.

Chris

"You can also hear there is some warmth (paradoxically) in this loud, aggressive and metallic sound of the cymbals."
Exactly. That is because in 'typical hifi' systems the aggressive treble (opposite of smooth and refined treble you talk about) extends and tinges further down to upper mids/lower treble that tends to sound thinner, unnatural, but detailed and present that many prefer, lacking warmth, completely not like real instruments.

I am not sure if I am making any sense or not;-)

Dazzdax and Nilthepil: No need for further elucidation.I know EXACTLY what you are talking about. That miserable element of treble reproduction you so accurately describe has been the most irritating aspect of sound reproduction I have ever encountered or known. The amount of money, time and frustration spent trying to eliminate or reduce its unwanted presence has been nearly criminal. And equally insane has been the large number of components, many of them ridiculously expensive, that have flooded the audio market and which almost routinely offer the very sort of treble emphasis/innacuracy that you so correctly and necessarily call attention to. Hopefully, some day in the not too distant future the hi fi treble issue, for the most part, can be put to rest so the listening experience can be less tense and frustrating and more genuinely satisfying and enjoyable.

Though I'm very pleased with my existing components, here is something I failed to mention, but should have. If you have tried a number of component changes but are still somewhat dissatisfied, you might want to re-examine your room's acoustics. I was able to get some assistance from a friend who brought in a spectrum analyzer, which revealed some sound related issues associated with the location of my seating and speaker positions. Making corrections with these as well as dealing with some wall and door reflections in areas of the room I was not previously aware of made a very significant overall change with regard to treble presentation. What I'm hearing now is smoother and more like the kind of sound I enjoy in a nice concert hall.