I too think of hifi terms with music as a reference. Music is a magical thing. When musicians are listening and playing with each other you'll know it. When they're not in sync, you'll know it. It's unmistakeable. To me, the ability for musicians to gell and play tightly together is PRaT. If a player is constantly early or late, the performance starts falling apart. In music reproduction there are obviously more variables. The musicians first have to get it right before any reproduction system can reproduce it. But great performances are great performances because they get everything right. When it's reproduced in a music system, everything has to be just as spot on at least in terms of rhythm. When it's not, it doesn't feel as "right" and you'll invariably be moved less.
