You are there vs. They are there

in my opinion. 

They are there. is how I would express it BUT with a bit of flavor. The players are in your room, but with space and dimensionality, not just there but with space amongst the instruments and vocalist.

I would like to best describe it as "walk in reality of the players" in your room"

now that is hard to do, if your room and speakers are not in full synergy

I think the correct way to word the question is, “they are there, or they are here”.  So the musicians can be there which means the music sounds like it’s between the speakers and behind the speakers. When you say, the music or musicians are here means that the music sounds between the speakers and projects the music in front of the speakers which gives the illusion that the musicians are here in your room. 

I have both setups in my house and for vocals and single instrumental music a lot of people like to hear the musician in the “they are here” presentation which is usually accomplished with single end amplification. Pushpull amps will give the presentation of “they are there” which is better for other types of orchestra and large scale music. For what it’s worth, I have both types setup in n my house and if I had to settle on only one sound or system, I would choose the “they are there” sound. I like it much better to see the performance in front of me rather than have the feeling like they’re in my room. 

The two dumbest phrases in audiophile lingo. Meaningless. 

Not "They are there" but rather "You are there." 

"They are there" puts them at their venue, but puts you nowhere.

"You are there" puts you at their venue listening to their acoustics from a near, center seat.  In this case, I would think that you would want to deaden the room as much as is feasible because you don’t want to add any of your own sound.  

"They are here" puts them in your venue listening to your acoustics, obviously blended with their acoustics recorded into the media.  Room deadening is less of an issue because this is the character of the venue that they are playing in and provides more of a sense of "liveness."