Live music, headphones, and speakers long

This is more of a comment than a question but I welcome feedback nonetheless.
I want to talk about the “location” of sound and music.

I was listening to quartet playing chamber music (unamplified) at a Christmas party. I walked around the room and listened from various positions, often with my eyes shut. No matter where I stood in the room, or how quiet the music was, it always appeared to come from and exist in three locations:

1. From where the musicians were seated.
2. From around me (room reflections and decays).
3. From in my head.

No one will be surprised by the first two locations but you may be surprised by the third. There are a number of reasons that one may not be cognizant of this property of hearing. One is because it doesn't with all sounds in all situations. A second is because we are very visually oriented. We see the violin “over there,” we know that the sound is coming from the instrument and we assume that is the only location we should perceive the sound to be coming from. And finally because it has always been important for our survival to know exactly where a sound (a predator for instance) is coming from.
I didn’t come across this 'sound in the head' phenomenon until I became an ‘audiophile’ and really started to analyze what is occurring in me when in the presence of an unamplified instrument. I find that it is still necessary to block out the visual distraction (i.e. close my eyes)of seeing the instrument "over there” in order to realize this dual location perception.

I have tried to articulate this before but I never got it quite right.
I used to talk about this as a “projection” of music from the instruments. Another word for this is 'action.' I would say that a great system had to be able to project sound from images such that the sound would wash over and engulf the listener. This is still very important but it falls short of telling the whole story.
I also used to confuse location 3 (in the head) with location 2 (around the room). I figured that a good system was one that could throw a huge, room-filling, room-energizing, soundstage and populate it with plenty of ambient detail and spatial cues. This too is very important but it doesn't tell the whole story either.
I now realize that a great system not only has to project the music and fill the room but that it has to put the music “in your head.”

Understand that I am not speaking metaphorically, nor am I referring to the brain’s neural processing when I say “in the head;” I actually mean the physical sensation/perception of music existing inside the skull.

This, I believe, is what many love about listening through headphones. One feels that the music is occurring in the skull. One feels the "music inside" and “inside the music.”
The feeling of music occurring in the head may be exaggerated by headphone listening but I submit that it is a phenomenon of hearing some sounds in some situations in the real world. In the three locations listed above, I rank it second in terms of strength as it is usually a much stronger sensation than room decays and reverberation.

This brings us to stereo systems using loudspeakers. I suggest that high end systems breakdown as follows in terms of locating the music:

1. Locates music as coming from the speakers.

2. Locates music as coming from a flat plane that extends between the speakers, on their axis. In other words: “music as wallpaper.”

3. Locates music as coming from an area that is wider than the speakers with the fore-edge of the soundstage along the axis of the speakers and the back edge of the soundstage many feet behind the speakers. If the system does not have ability to project sound out into the room, I like to think of this presentation as "music in a bubble." The listener will always sense a gulf between himself and the music that is in the bubble, 'over there.'
This is probably the most common presentation of high end systems. It is what I hear in just about every room at every show.

4. Locates music as in 3. but moves the fore-edge of the soundstage well in front of the speaker plane and also presents music (ambient information) as coming from the sides of the listening position. Assuming that the system has good natural 'action/projection' this type of system should sound very good, all other things considered.

5. Locates music as occurring everywhere in the room and beyond the room. The soundstage is the room and the room is the soundstage. The idea of a delineated soundstage 'area' virtually disappears because the fore-edge of the stage is now behind the listening chair. The listener either feels like he has been transported to the recording venue or the recording venue has been grafted onto his listening room. With this presentation and the sound properly propelling forward from the individual images I used to think that this was a good as it gets.

6. Locates music as in 5. but also locates it in the listener's head. One may never truly believe one is in the recording venue unless the music from the performers feels as if it is physically moving through the area between the ears, in the skull. When this magic happens you are truly engulfed in the music. The music is in you and you are in it. The distinction between the space inside your head and the space around your head is blurred. It may in fact be incorrect to use the phrase "music is in you" because the distinct impression of "inside" and "outside" starts to fall apart. The listener, the room, and music no longer appear as three disctinct entities.
With this presentation you can still choose to focus your mind and point to the exact location of a 3-D image of an instrument that may appeat 20ft. behind the right speaker but you can also let go and physically sense the sound of that instrument, the presence of the vibrations of that instrument, in your skull.