While it certainly is a challenging vocal performance, I don't think this one is a matter of his voice giving out. I saw him on Saturday matinee. He was spectacular as always, but compared to when I saw him in March, he was not in full voice, in my opinion. Hit the big notes and drastic octave changes, but some sounded grainy. During the bows at the end, he definitely looked spent and blotchy, and he did not stage door. I think the poor guy is sick. It seemed to me that another cast member might be coming down with the same thing.