Touring artists have several advantages that most artists don't have. The most important thing is that they get very early load-in and sound checks. The stage guitars probably have been at that venue for many hours, out of their cases, on the very stage where they will be played. And even then, if you look at the actual logistics of the guitars that they'll actually play, performers almost never take the guitars out of their side rack. Those are emergency guitars that can be used for a quick change, but they'll usually play a guitar that the stage tech hands them directly, which probably goes through a little bit of tuning before being handed to the guitarist. Then they rarely play the same guitar for more than 2-3 songs, if they're lead players who use bending techniques.I never think that constant re-tuning is right. If you ever watch any of the big touring artists, while some are rotating a trunk full of different axes for different songs, the ones that don't are never standing in front of 50,000 people constantly touching it up. While they certainly have traveling guitar minders on the road, these guys know how to set one up where that sort of thing rarely happens, and anyone can learn that.