Just to add a bit to 61's post, there is always the actual room sound aspect of recording vocals, piano, acoustic guitars, etc. that can help an engineer create a convincing soundstage, even within the artificial environment 61 so well describes. I am about to begin a recording project that involves a "clicktrack", acoustic guitar, guide vocal, percussion, bass, piano, horns, in that order, and I will try to keep as much of the natural room sound as possible even with much overdubbing.
If the actual room sound is not that great, I will add a different room sound as discretely as I can.
If the actual room sound is not that great, I will add a different room sound as discretely as I can.