Depends on the music. I rarely try to picture myself a part of an audience or imagine myself in some kind of room.
On good listening sessions, I can let the music take over and program my emotions for however long it goes on.
Since I'm as likely to be listening to musique concrete as J-pop, be-bop or early-90s alternarock, I can't really say I drift away with it. But whatever it is, the effort I've put into better listening equipment makes the experience a lot more immersive, even if I'm not trying to listen to details or spacial cues.