You'd have to ask him abd/or the composer or musical eirevtor. It could be many things including: that's what they wanted -a lower key, he is after all an older character than the person he played in Piazza; if it is because of Morrisons own voice, singing a higher score for one night is different than singing it 8 times a week!
If we're not having fun, then why are we doing it?
These are DISCUSSION boards, not mutual admiration boards. Discussion only occurs when we are willing to hear what others are thinking, regardless of whether it is alignment to our own thoughts.