what does "Air or a Halo around instruments" mean?

Last Saturday I went to the symphony. I heard Beethoven.
I did not hear any air around any of the instruments in the orchestra, nor around the piano playing the piano concerto.
And 3 weeks ago I went to a 3 day folk music festival with all music played through a concert sound system, even the classical guitarists. I never heard any air around instruments there either.
What I did hear at both the Beethoven concert and the folk music festival was music that had a wholeness to it. The symphony was as one instrument with many many individual colors. And music through a sound system is completely as one, no matter where on the stage the person is playing.
I have often read the phrase "air around instruments" in reviews. But is this not just one of those "audiophile sound characteristics" rather than what music really sounds like?!

Moving air is what music is!
Most music reproduction systems tend to lose much of the "moving air" that is the music. The dynamics and clarity of live music just vanish. Ever listen to your system after coming home from the symphony??!! Does it sound like you are sitting in the foyer, or on the main concert floor?
A system that has "air around instruments" may have a bit of the dynamics and details of the live experience. And perhaps that's what this refers to.
But at a concert, I never hear "air around instruments" but I do hear a lot of moving air. To me, it seems like that is a difference. But maybe not.
BTW, I do not have perfect pitch or hearing.