Disney are making a number of early morning performances during the preview period exclusive to Annual Passholders. To quote the Passholder newsletter:
"To celebrate the premiere of Finding Nemo?The Musical at Disney's Animal Kingdom? Theme Park, we've set aside each day's first seating between Dec. 1?10 for valued Passholders like you!
NOTE: ADVANCE sign-up is REQUIRED."
The signup can be done at the passholder website at https://secure.disney.go.com/wdw/passholder/passholdersGate?id=PassholdersGatePage