The Disappearing Act

OP asks if the disappearing happens uniformly -- with all recordings.

For me, definitely not. Only with a few LPs and a with a few CDs. In my experience, most recordings and subsequent transfers to media suck; probably because of weak technology, or possibly because the responsible engineers "had other ideas" about how things should sound.

But don't get me wrong -- I still enjoy this hobby, and I still love music. Most often, the disappearing I experience comes in a brief moment as a shocking surprise, and it transfixes me. In those moments I connect with the music, and -- forgive the metaphor -- I become one with the music.

@lalitk My speakers disappeared long ago. It happened gradually as I dialled in the sound with relatively small but significant improvements which, if you can imagine it, pulled the sound from 2D against the plane of the speakers to 3D away from them until they just disappeared.

Almost everything I play is simply in the room.

It happened gradually as I dialed in the sound with relatively small but significant improvements

This is my experience. Many tweaks who are often dismissed were a big part of the disappearance. First was the footers Then the electric. . A $2 footer tweak started the journey. It wasn’t that the tweak was so astounding. it was the very fact that I heard a difference at all. I was quite skeptical. Not now. I discount few things.

very recording dependent for me. Some albums from the 60s already have it but .likely not. Also genre dependent, studio dependent, etc. 

As others have mentioned, some of the early stereo recordings from the 60's are particularly egregious. I listened to some Mommas and Pappas that were cringe worthy. Especially on headphones. Many songs start with sound from only one channel. Weird feeling of sound in one ear and a vacuum sucking on the other (with phones). No disappearing components from that.