Nicely put, Guest Dave. However I do believe that what you hear on the DVD is what, for the most part, the audience hears. The audio is then 'enhanced' using the best technology available to give a cleaner, near perfect, end result on the DVD. I doubt they could lay an entire new audio track over the video (or vice versa) and have it match that good, right down to the tiniest picks of a guitar or violin, or the singer's voices and breaths themselves. But I admit some for sure is added in the studio after the concert. Common practice, no doubt. What do you think Jim ? Something tells me you are nearby.