It's not just the sound of a room with an audience that differenciates a live show from a recording. Even in "live" recording, the absence of intimacy and immediacy are striking. It is not unlike the difference between live theater and movies or television. It is why we are willing to pay more for a concert ticket than we are for the, more technically perfect, recording of the concert. Another reason for precision and sound quality in recoring is that repitition is the severest of examiners. The CD will be played over and over and, if there are flaws, they will pop out like pimples at a sock hop.