Sound stage

Its best to think of all recordings as having a soundstage. TWo channel recordings are considered stereo. The soundstage is artificial based on how the recording was miked and mastered but exists nonetheless. Some specialized or rare recordings use a simple two mike recording approach and attempt to reproduce teh soundstage at the live event. These are worth finding and seeking out. The old Mercury Living Presence and newer Dorian and Mapleshade labels are three with many recordings that contain a very natural soundstage due to production techniques.

Unless listening on headphones or on a stereo hifi not set up to address soundstage at all as a result of speaker placement, all recordings have a soundstage in that the "sonic cues" produced live are in the recording and affect teh results in terms of soundstage and imaging. Even with mono recordings, though again these will tend to have everything more dead center and sonic queues captured in the better ones can still provide a sense of 3-d ambience. You have to have a hifi that delivers enough detail to capture all the subtle sonic queues accurately and have things set up properly as well in all cases.

"How do you know when its right?"

To start, get something like the XLO Reference Recordings CD, which has tracks that will walk you through where you should be hearing things. If you hear what the narrator tells you should be hearing, then you're on the right track.

back when stereo first hit, soundstage and imaging was a big selling point. You can find old lp releases on Mercury Living Presence and others that go into great detail in teh cover notes how the recordings were made and what was located where during the recording session.

Soon after the novelty wore off and most people did not pay attention to such details. Except us audiophiles, of course.

Yea especially in early Beatles stereo pressings L:)

Staging is a function of both recording and playback equipment. I'd also agree with previous posts that there's no "perfect" paradigm that you're seeking for all recordings. Highly processed or manipulated recordings can even cause you to sense images that seem to be coming from behind your head (check out many of the Qsound recordings for this effect).

Heavy pan potting (Theme from Shaft, among many others) can create shifting instrument locations that are part of the intended artistic effect. You can seek out minimally miked records for purist stereo effects, but that approach is too limiting (in terms of music that I enjoy) for me.